- MPs vote to raise tuition fees to a maximum of £9,000 per year in England, by a majority of 21
- A day-long demonstration in Parliament Square flares into violence
- The Prince of Wales' car is attacked by demonstrators in central London
- Reporters: Justin Parkinson, Andy McFarlane and Lucy Wilkins
That concludes our live text coverage of a day of protests and high drama at Westminster. The coalition got its plans to raise tuition fees through the House of Commons, but not without a rebellion by Lib Dem and Tory MPs. The Prince of Wales' car was attacked in central London by anti-fees protesters and demonstrations involving thousands of people took place in and around Parliament Square. Thank you for joining us. Live video footage continues on this page and on the BBC News Channel.
The clean-up operation is under way in Parliament Square, where a lorry is collecting the barriers used by police to try to contain the protesters earlier. There have been 22 arrests today, according to Scotland Yard.
Parliament Square is now empty of protesters. The area is strewn with rubbish, while some of the surrounding buildings have been daubed with graffiti and a few windows have been broken.
There is going to be a lot of mess to clean up in Parliament Square over the next few days, the BBC's Ben Brown reports. Some bonfires are still burning and there has been damage to buildings and statues, he adds.
Hundreds of protesters are being ushered across Westminster Bridge, which runs off Parliament Square.
Scottish Secretary Michael Moore pays tribute to fellow Lib Dem MP Michael Crockart, who quit his government role as an aide to Mr Moore in order to vote against the fees rise. He says: "I respect the way he and other colleagues have considered the issues before coming to their conclusion... I am glad that he continues to support the coalition, and I know he will play a constructive role in our efforts to rebuild and rebalance the economy left to us by the last government and create a fairer and more prosperous country."
London Mayor Boris Johnson thinks the attack on the car containing the Prince of Wales and Duchess of Cornwall was "very worrying", according to a spokesman. He is "appalled by the scenes of violence this evening... It is an insult to our democracy," the spokesman adds.
The few hundred remaining protesters in Parliament Square are expected to be marshalled over Westminster Bridge to the South Bank and then dispersed, the BBC's Ben Brown says.
Miller writes: "Why can students not contribute to their education, and only if they make above £21k. What is the alternative? Higher taxation? More Cuts? The country is on its knees, and everyone needs to make a contribution."
Talking about the House of Commons' decision to raise fees, Labour leader Ed Miliband says: "Today's vote is a disaster for young people and families up and down the country, who now face the prospect of significantly higher fees and higher debt when they go to university. But it is also a disastrous day for Nick Clegg and his leadership of the Liberal Democrats. Clegg and his fellow Lib Dems who have supported this proposal have destroyed their party's claim to stand for fairness and opportunity for many years to come."
Scotland Yard has condemned the "outrageous and increasing levels of violence". A spokesman says: "This has nothing to do with peaceful protest. Students are involved in wanton vandalism, including smashing windows in Oxford and Regent Streets. Innocent Christmas shoppers are being caught up in the violence and disruption."
Jack in London writes: "I would like to congratulate all students who have protested peacefully during the last few weeks. It is better to lose with principles than win having given them up. Today is a truly dark day for education."
The Prince of Wales and the Duchess of Cornwall were "unharmed" after the car they were travelling in was attacked by tuition fees protesters, a Clarence House spokeswoman says.
Miller writes: "Why can students not contribute to their education, and only if they make above £21k. What is the alternative? Higher taxation? More Cuts? The country is on its knees, and everyone needs to make a contribution."
The demonstrators who attacked the Prince of Wales' car earlier threw a can of white paint at the vehicle and shattered a window, the BBC learns.
tweets: "Nick Clegg didn't stick to his plan. Why should the protesters stick to theirs?"
Protesters have attacked the Oxford Street branch of Top Shop, the BBC understands.
tweets: "Absolutely gutted at what's happening. If any of these louts are students they should be ashamed, but I doubt they are."
Protesters are now attacking the Supreme Court builiding in Parliament Square. They are not thought to have got in.
Despite the attack on the car containing the Prince of Wales and Duchess of Cornwall as it travelled through central London, the couple arrived at the London Palladium theatre for the Royal Variety Performance, the Press Association reports. The show began on time.
The atmosphere in Parliament Square appears to be calming, with more demonstrators heading off.
An Associated Press photographer saw demonstrators kick the Prince of Wales' car in London's Regent Street, it is reported. The vehicle then drove off, it is added.
The Associated Press is reporting that protesters in London have attacked a car carrying the Prince of Wales and the Duchess of Cornwall. The BBC has not confirmed the report.
Riot police have prevented demonstrators from entering the Treasury, the BBC understands.
Anthony Wilkinson, Lima, Peru, writes: "A truly terrible, black, black day for UK education"
Business Secretary Vince Cable says his Liberal Democrats have faced a "difficult choice". "By no means all" students oppose the fee rises, he tells Channel 4 News.
Martin Shapland, chairman of Liberal Youth, says increasing the tuition fees cap will mean students graduate with a "huge burden of personal debt". "Liberal Democrat policy remains the abolition of fees. I am saddened that we have been unable to implement this, but such is the nature of coalition politics," he adds.
tweets: "@BBC_HaveYourSay I was going to do a PGCE after completing my BA. Now, thanks to government, I won't afford it. A teacher has been lost!"
Demonstrators in Parliament Square are throwing missiles at police. "It's pretty nasty here and it's all blown up in the last few minutes," the BBC's Ben Brown says.
tweets: "Groups being let out of kettle half way up Whitehall many quite traumatised. Tension still high #dayx3"
Superintendent Julia Pendry of the Metropolitan Police says eight police officers have serious injuries. She adds that, each time police try to release demonstrators from containment areas, violence flares up again. She says that officers will remain in place until the trouble stops and that the Churchill statue in Parliament Square has been defaced.
Some protesters are attempting to smash the windows of a government building in Great George Street, just off Parliament Square.
A breakdown of voting among the Lib Dems earlier. Twenty-one of the party's MPs rebelled against the plans to raise fees to a maximum of £9,000 a year, with 28 supporting the government and eight abstaining. Among those opposing the motion were former Lib Dem leaders Sir Menzies Cambell and Charles Kennedy, and party president Tim Farron. Deputy leader Simon Hughes abstained.
The BBC's Mark Georgiou reports: "At the police line by Westminster Abbey a small crowd has gathered. Youngsters mostly trying to persuade officers to let them out. Some are cold and tried, others desperate to use the toilet. Mostly they have just had enough and want to go home. In twos and threes they are starting to be allowed out but only after being filmed by the police."
Police Federation chairman Paul McKeever says "kettling" tactics are an "inevitable outcome" when police are faced by demonstrators who do not want to protest peacefully. He says the bravery of officers facing attack from "missiles, including snooker balls, paint balls and pyrotechnic devices" should be recognised.
A statement from NUS president Aaron Porter reads: "This is not the end, and our protests and our work have sparked a new wave of activism which will grow stronger by the day. We stand ready to fight the next stage of this campaign together. Our future is at stake."
One London School of Economics student tells the BBC that the policy on fees is "unfair and undemocratic" and pledges to carry on demonstrating in a bid to force the government to scrap its plans.
BBC Political Editor Nick Robinson says the concern for the government will be now that some MPs "have a taste for rebellion", they may do it again.
Mr Cable says he has "no regrets" about being part of the coalition, despite the fact 21 Lib Dem MPs voted against the government.
Business Secretary Vince Cable says the policy has been passed by a democratic Parliament and that the details must now be explained to the public. With thousands protesting outside Westminster, he tells Sky News that he accepts government has yet to "get the message out" about the benefits of the plan.
National Union of Students president Aaron Porter tells Sky News he's "incredibly disappointed" at the result of the vote. "Evidently more Lib Dems decided it was important to be subservient to David Cameron than the people who voted for them," he adds.
tweets: "@BBC_haveyoursay Tuition fees now have a maximum of £9000... A sad day for the future of the nation"
Demonstrators can be seen pushing at police lines using large metal fencing in Westminster. Officers with riot shields are holding them back.
The second motion relating to a rise in the cap on tuition fees has been passed with an identical majority of 21.
Asked if he would promise to cut the cost of education for students, Ed Miliband says the lesson of the vote had been to never make promises unless you are sure you could keep them.
Labour leader Ed Miliband says it's a "bad day for families and young people across the country". He adds that the Lib Dem decision to go back on their pre-election pledge to vote against tuition fee hikes damages trust against politicians in general.
BBC political editor Nick Robinson writes:
"Three-quarters knocked off the government's majority... the biggest Lib Dem rebellion since the party was formed... a coalition with a healthy majority having to haggle, woo, persuade to get its policy as the streets around Westminster were filled with angry protesters.This will come as a relief to the coalition but also a warning of what could lie ahead."
The National Gallery says about 150 students from universities around the country are staging a sit-in protest in its Impressionist Rooms.
With the second vote under way - relating to the lower cap of £6,000, beyond which universities would be forced to put measures in place to aid poorer students, Supt Julia Pendry says the violence being perpetrated against police outside Parliament is continuing. It will take some time to put a plan in place to disperse those demonstrators in the containment area, she adds.
EP Finlason in Oxsted, Surrey writes: "This rise in fees is the inevitable result of the current obsession with tertiary education. Places at university should be free but restricted to only the brightest 10% or so of students, whatever their background. Sending large numbers of people with average intellects to university puts an unbearable strain on overall funding."
The result of the ballot was 323 in favour of the raising fees and 302 against. The slim majority of 21 was greeted with muted cheers from the government benches.
Parliament has voted to raise tuition fees at English universities to a maximum of £9,000 per year.
Police have arrested four people following a sit-down student protest in the road outside Belfast City Hall this afternoon, BBC Belfast reports. Around 150 students were taking part in the demonstration. Queen's University Students Union said it did not organise the march, which was mainly attended by secondary school students.
One person who will not be among the "ayes" is Conservative MP Lee Scott. BBC Political Editor Nick Robinson understands he will abstain and therefore has had to resign his position as an aide to Philip Hammond, the Transport Secretary.
Voting is under way on the first motion - which would raise the cap on tuition fees to £9,000 per year from September 2012. The result is expected within 15 minutes.
Mr Willetts finishes, and the Speaker orders voting to begin.
The BBC's Laura Kuenssberg understands that Lib Dem deputy leader Simon Hughes, who had indicated he would not vote with the government, will abstain - rather than opposing the plans.
tweets: "One Conservative tuition fees rebel MP has just told me: 'I have never felt so low.'"
David Chatterton in Winchester writes: "On the subject of student fees, I have yet to see reference to the situation should a graduate decide to join the 'brain drain'. If student loans are collected via income tax, how does the government intend to recover the amount if the student emigrates? Surely the current situation provides an added incentive to do so."
tweets: "Universities minister David Willetts making a far better fist of defending fees than his boss Vince Cable did five hours ago."
It's standing room only now in the Commons, as David Willetts argues that tuition fees have so far had no impact on access to university among people from poorer families. He says a smaller proportion of people from disadvantaged backgrounds go to university in Scotland, where study is free.
May in London writes: "The government's main defence is that students will only be paying once they earn £21,000 and above. The point is whether they pay it now or later they will still be paying more than the generations before them who are responsible for the crisis but aren't paying for the mess they've created."
In his closing speech, Universities Minister David Willetts says the reason for the passion behind the MPs' debate is that "all of us care" about the future of universities and the young people of the country. But, he adds, when in government, all three major parties have concluded that the way to fund student learning is to provide loans from the taxpayer - to be repaid by graduates.
Chris Differ in Glasgow writes: "The Lib Dems are going against a promise they made in the run-up to this year's general election. If the government goes back on their promise shouldn't we all be on the streets demonstrating?"
tweets: "Conservative MP Tracey Crouch says she still plans to abstain."
Another Lib Dem is to resign as a ministerial aide, the BBC understands. Cardiff Central MP Jenny Willott will oppose the hike in fees in tonight's vote.
In the Commons, shadow business minister Gareth Thomas points out that despite its economic woes, Ireland is not proposing similar cuts to the UK in university funding or planning to triple student fees.
A protest in Brighton, East Sussex, passed off peacefully with only one arrest, which was for a public order offence after someone failed to remove an offensive banner from display. Sussex Police said around 150 people took part in the march.
The benches in the Commons are filling up again as - after hours of debate - MPs prepare to vote on the proposals.
London Ambulance Service tells BBC London that crews have treated 19 people so far, with six taken to hospital.
Simon Reed in Nottingham writes: "I wonder how many of those who received free university education and now say that it's fair to increase fees will be donating 9% of their wages until contributions reach £27,000 to help reduce the deficit."
Seven people have been arrested in total, while three officers are injured, according to the Met Police.
A large fire is blazing in Parliament Square, where a wooden container has been set alight to the cheers of the protesters.
Away from the main protest in Parliament Square, police estimate there are a couple of hundred people at the rally on Embankment, the BBC's Tony Brown reports.
Chief Supt Julia Pendry, of the Metropolitan Police, says officers have come under sustained attack from protesters. Asked about students' complaints of "kettling" tactics, she says demonstrators are being allowed to leave the Parliament Square containment area from the Whitehall end. Unions involved in the protests had failed to stick to their agreed rallying routes, she added.
tweets: "Odd experience coming back into press gallery from fiery demo in Parliament Square. MPs cut off from noise as if nothing going on outside."
The BBC's Laura Kuenssberg says there has been a very heavy police presence inside the Palace of Westminster throughout the day, much heavier than usual.
The BBC's Paul Lambert says police dressed in riot gear and carrying shields have been seen going in to the Palace of Westminster.
tweets: "@bbc_haveyoursay The students protesting really just do not understand, or do not want to understand the actual policy. An excuse to fight."
It's less than an hour before the vote begins in the Commons, and the BBC's Mark Georgiou reports that as darkness falls a lull is happening in the push and shove of the protest. Police lines are being rotated, and some officers are coming away covered in what looks like paint.
About an hour remains of the Commons debate before the vote is held. Coalition attacks on Labour's 50% target for university admissions are "attacks on opportunities for young people", Labour MP Pat McFadden tells MPs.
Tom Waters in Cheltenham writes: "I'm a student, and I'm fully in favour of the increase in fees. The fact of the matter is that having a degree nets you an average of £100,000 in increased income across the course of your life. It's fair that people pay for that privilege."
London Ambulance Service tells BBC London it has treated six people for injuries at the student protest. Unable to say at this stage how serious those injuries are.
Some protesters being pulled from crowd and arrested, the BBC's Mark Georgiou reports from Westminster. Others are pulled out for medical treatment. Keeping a lid on this kettle is a hard-fought affair, he says.
Details are emerging of Lib Dem ministerial aide Mike Crockart's resignation letter. In it he tells party chief whip Alistair Carmichael the rise in potential student debt will "seriously impact on people's choices". He goes on: "This is especially true for those students from poorer backgrounds, many of whom have no role models in their schools or families to demonstrate to them the benefits which can accrue from a university education."
A police officer has sustained a serious neck injury after being knocked unconscious, the BBC's Andy Tighe reports. He has been taken to hospital.
tweets: "@BBC_HaveYourSay To Mr Davis: Shouldn't those office workers sat at their desks be protesting instead of sitting watching the UK fall apart?"
The BBC's Laura Kuenssberg says Lib Dem Mike Crockart has quit his post as a ministerial aide to vote against the proposals.
The BBC's Andy Tighe reports that a Mounted Branch police officer has been taken to hospital with leg injuries. Three arrests have been made during today's protest: two for assault on police, and one for being drunk and disorderly.
The BBC's Phil Herd, in Westminster, says police are trying to reinforce the line of officers. However, there is a lot of pushing backwards and forwards against the weight of 3,000 or so protesters.
Melanie Frame in Bangor, Wales writes: "I am shocked at the scenes in Parliament Square. These are not disaffected youth rioting, these are our brightest children, the ones who studied hard at school so they could go to university and make a bright future for themselves. They are being charged by fully grown men in riot gear and by horses."
tweets: "A good debate this. It shows how the Commons has revived since the election, largely thanks to new MPs who have made many of best speeches."
JC in Birmingham writes: "In response to Willam Hague's insistence that students with lower paid jobs will be better off - we students do not want to graduate with extortionate debts of an estimated £40,000 only to be better off earning less. Surely this defeats the point of going to university at all?"
Charlotte Henry, vice-chairwoman of Liberal Democrat Youth, says its members have been telling the party's MPs they are "deeply worried" about young people starting adult life with massive debts. She adds that students will keep the pressure on the government.
E Davis in Littlestone, Kent writes: "Shouldn't all these protesting students be sitting at their desks learning, instead of making a nuisance of themselves and costing the taxpayer big money to pay for police overtime?"
The Metropolitan Police says officers will use tannoys to talk to those within the containment to explain what is happening.
A Metropolitan Police statement says it has been necessary to put in a "containment" in Parliament Square due to the level of violence officers are facing. Missiles thrown at police include flares, sticks, snooker balls and paint balls.
tweets: "Senior Lib Dem source tells me he reckons 20 of their MPs will vote against #tuitionfees, 'but we think we can peel one or two of them off'."
The BBC's Mike Sergeant says some of the police tactics will be seen as controversial.
The scene in Parliament Square is fairly intimidating, BBC reporter Phil Herd says, with plenty of things being thrown at the horses and firecrackers going off. There appears to be one injured policeman near him.
Police horses charge the crowd, pushing them backwards, footage from the news helicopter shows. Protesters retaliate by throwing things at them.
The BBC's Mark Georgiou says a police officer has been thrown off his horse and been injured in the protests around Victoria Street.
Robert Flello, Labour MP for Stoke-On-Trent South, says the government was conducting a shamefully short debate on a subject that would rage on and on outside.
Thousands of protesters remain in Parliament Square, says the BBC's Mike Sergeant in the midst of the protest. He says most of the protesters expected to remain there until the vote, rather than moving to a planned rally a short distance away.
Back in the Commons, John Leech, Lib Dem MP for Manchester Withington, says he will vote against the proposals because they will discourage some young people from going to university.
Amy Martin-Madeley in Cleveland, Ohio, US writes: "In a way I can understand the anger and resentment behind the protests, but having just graduated from a university in the US I cannot really sympathise with what in my view are still pretty cheap fees at £9,000 a year."
Foreign Secretary William Hague insists the proposals were not a graduate tax, but a progressive means of repayment. Many lower earners will actually be better off under the proposals than the existing system, because they will not have to pay anything back until they earn £21,000, he stresses.
The BBC's Paul Mason says some students appeared to be moving away from Parliament Square. Footage shows a very small fire burning on the grass of the square, fuelled by placards.
Sean Byrne in Lanark, Scotland, writes: "I'm amazed that people think tuition fees are a good thing. The money spent by the government on the fees should be thought of as an investment the country as a whole benefits from. The graduates are our future managers and leaders and so generate the taxes through their hard work!"
Foreign Secretary William Hague, standing in a very busy Commons lobby, tells the BBC the UK needed to continue to have world-leading universities, and that would only happen by putting the necessary resources into them.
Paul Calzoni Weiss
tweets: "@BBC_HaveYourSay I'm an American, I like the UK system because it is accessible to all. This measure will make the system American, not good."
Labour MP David Lammy says students need to know what they are getting for the contribution they are making - the size of a tuition class, for example.
Lisa in Liverpool writes: "I am for the fee rise, as it will encourage students to spend their time at university in a more productive manner. The increase in fees will increase attendance at university and increase the quality of degrees. What does worry me, however, is that with such a lengthy payback time and by allowing an interest rate to be imposed many students will be burdened with these repayments for life."
Labour's Diane Abbott says the prospect of £40,000 or £50,000 of debt is huge, and politicans need to put themselves in the position of ordinary people.
Atina Shirvanian from Liverpool
tweets: "@bbc_haveyoursay as a history student in Liverpool my department has already faced cuts. Anymore cuts and it will face closure"
The BBC's Mark Georgiou describes Parliament Square as one big kettle. The police line at the Westminster Abbey corner is not letting anyone in or out. Police seem happy to contain crowd.
Sam Gyimah, Conservative MP for East Surrey, says people from the most deprived areas are not getting to university and the system needs to be reformed.
OE, London, texts: "As a medical student, the prospect of paying £40k to become a doctor would have probably led to me becoming a lawyer or banker. Talking to my friends, I am not alone in this."
Labour's Tristram Hunt calls the policy an "assault on the entire ethos of the British university".
Ollie Micklem from Chelmsford
tweets: "@BBC_HaveYourSay the offering of courses such as harry potter studies don't deserve to be funded by taxpayer so the gov is right in the cuts"
Conservative MP Andrew Percy says the government's stance is wrong. He says students are already making choices based on finances, rather than on what is best for their education.
Away from Westminster, Scottish Education Secretary Michael Russell has promised that Scottish students studying in Scotland will not pay tuition fees, regardless of the results of today's vote. He told an NUS and University and College Union rally that a green paper to be published next week would present a range of options but that "the state will remain the primary provider of education".
SDLP MP for Belfast South Alasdair McDonnell says little thought has been given to the impact of the changes on Northern Ireland, or the other devolved nations. An independent review in Northern Ireland is expected to recommend preserving the fees cap - but Mr McDonnell is concerned about how universities will be funded.
Protesters in Parliament Square are trying to attack police lines with metal fences ripped from the centre of the square. Riot police face them with batons drawn and helmets on, reports the BBC's Dominic Hurst. Students are chanting "shame on you".
John, in Dundee, writes: "As a student I completely support the fee rise in England and if it should come, Scotland. The UK has spent too long spending money on luxuries it can't afford and it's only fair that students should give something back to the fantastic service many universities provide!"
Alternatives being put forward by the National Union of Students "seem to change every few weeks", says Ben Gummer, a Tory MP. But, he adds in a dig at Labour, "at least they have alternatives". Mr Gummer says the opposition has failed to properly explain in any detail its proposed graduate tax.
The BBC's Mark Georgiou reports: "Pall of green smoke from a flare drifting across Parliament Sq; the odd firework exploding. Nobody moving anywhere."
Conservative Ben Gummer says "the tenor of the debate is doing more to put off aspiring students" than anything contained within the proposals.
The BBC's Paul Lambert, in Parliament, says that in the last 10 minutes three protesters have been asked to leave the public gallery for chanting.
The BBC's Dominic Hurst reports: "Students rip down fences in parliament square. Missiles flying."
JW in Thame writes: "I have two reasons why the bill should be passed. Firstly, as a taxpayer, I don't want to pay for others to study for a degree when, secondly, there are many apprenticeship schemes, colleges and training programmes that provide similar, if not better, career training."
There is a stand-off at the corner of Parliament Square, the BBC's Mark Georgiou reports. "A beer can lobbed at police line. Loud, tense and police putting on riot helmets".
Rushing things through amid the current level of concern, without proper parliamentary scrutiny, is a recipe for bad policy, says Greg Mulholland, the MP for Leeds North West.
Will Butler, in Parliament Square, texts:"Why should young aspiring people who have done nothing wrong during the economic crisis have to foot the bill for someone elses mistake?"
tweets: "Contrast between sides now debate under way, several big names on Lab side - Blunkett, Straw, Dobson, Abbott. Few famous faces on govt side"
Lib Dem Greg Mulholland - who failed in his bid to delay the vote through an amendment - says the debate should not be happening today in the form it is, just a month after the government announced its proposals. "Sometimes governments are wrong and sometimes you have to have the courage to stand up and say so, that's what I'm doing today," he adds.
tweets: "@BBC_HaveYourSay 200+ PCs on Horse Guards Avenue ready to intercept any marchers coming from Trafalgar Square down Whitehall."
Former education secretary David Blunkett says Labour's introduction of tuition fees enabled many more people to go to university and was backed up by bursaries. He says the current proposals are fair neither to young people and their families, nor to universities.
tweets: "@bbc_haveyoursay Vince Cable making a lot of sense, pity more students aren't watching this... "
tweets: " Only with Denham's peroration did Tory backbenchers start rumbling: "What alternative have you got?" shouted Gavin Barwell."
The BBC's Dominic Hurst, in Trafalgar Square, reports: "Ugly mood as a hardcore of hundreds of students runs towards Parliament Square. Many are armed with sticks; there are some scuffles with riot police."
Tiffany Smith in London writes: "As a PhD student and visiting university lecturer, I urge MPs to vote against proposals today for the future funding of Higher Education, in particular the withdrawal of public funding for the teaching of the Arts, Humanities and Social Sciences. I am deeply concerned both by the rapidity with which decisions are being made and the ill-considered assumptions that underlie the proposals."
Back in the Commons, Conservative MP David Evennett says: "It's all very well [for Mr Denham] to wring his hands here but they were the government that caused the problems."
Mr Denham wraps up by pleading with those who have been "wrestling with their consciences" to vote down the proposals.
"Future students must be looking at this debate and wondering why it is such a laughing matter," says John Denham, in response to comical jeering from the coalition benches.
Some students break away and run down The Mall towards riot police, reports the BBC's Dominic Hurst.
Shadow business secretary John Denham says the scholarship scheme announced at the weekend to help 18,000 students from the poorest backgrounds is an admission the proposals will put people off going to university.
tweets: "The Commons ushers seem to be having problem in public gallery at tuition fees debate, which is only half full."
Shadow business secretary John Denham says fairness must not just be judged solely on how much graduates pay but also by how many people have the chance to become graduates in the first place.
The crowd at Trafalgar Square is now several thousand strong, the BBC's Dominic Hurst reports. Among the noisy students are some with scarves and hoods covering their faces.
tweets: "A good authoritative speech from Denham, well-argued, lots of humour, but he's had a far easier ride than Vince Cable."
Asked whether he supported his predecessor Lord Mandelson's proposed £1bn in cuts to the business budget, shadow business secretary John Denham admits higher education would not have emerged unscathed by those plans - but adds it would not have been cut by 80%.
Brian in London writes: "It simply isn't fair that binmen and postmen pay for students to study media studies through their taxes. It is surely fair for those students to pay, when their salary allows it in the future, for their own education."
By 2016, when the first students to face increased fees might begin paying back their loans, the £21,000 figure at which repayments would be triggered would be worth roughly the same as the current amount - contrary to government claims that graduates won't have to repay loans until they are better off, John Denham says.
If this fee increase goes through, English students and graduates will face the highest fees of any university system anywhere in the developed world, says shadow business secretary John Denham.
tweets: "John Denham making far better speech than Vince Cable because MPs are allowing him to."
Mr Denham accuses David Cameron of having been the architect of university cuts when an adviser to the last Conservative government. The difference now is that he has Liberal Democrat support, he adds.
The risks of the policy are so high and the consequences so unclear that "no sane person would rush it thorough without proper debate", argues shadow business secretary John Denham. But, he says, the government has not even presented the white paper to say how the proposal would work.
Mr Denham says it is hardly surprising that university leaders have backed the plans - after they have been told it's the only option on the table.
Mr Cable's shadow John Denham says the debate is about something much more important than the future of the Liberal Democrats. He calls on all Lib Dems to vote against the plans, rather than abstaining.
Lib Dem deputy leader Simon Hughes, who has said he won't support the plans, demands to know how the government can be sure it is right when it argues that annual fees of over £6,000 will only be charged in "exceptional" cases.
tweets: "Cable struggling through arguments slowly, patiently, methodically, but faces noisy, hostile Labour MPs and no help so far from Tory side"
Mr Cable says he's keen to encourage more private-sector funding of universities and indicates that, in future, public sector contributions will amount to just 40%.
Fifty university vice-chancellors have endorsed the coalition plans, Mr Cable says.
tweets: "Now is the time for MPs to decide if they want to lose their jobs in four years, or hold on to their dignity."
Shadow business secretary John Denham asks which other major spending programmes have been cut by 80%. Mr Cable points out that the options for his department - business, innovation and skills - were limited, given 70% of its spending was on universities.
As MPs debate in Parliament, a group of several hundred chanting students is marching down the Strand towards Trafalgar Square, led by a police escort. It's noisy but peaceful, reports the BBC's Dominic Hurst. They chant: "You say cut back, we say fight back."
Josephine Hyde-Hartley in Bacup writes: "Education, like information, should and could be free from cradle to the grave in a truly progressive democracy like the UK. Like health care, education is a public good."
Labour MP Jack Straw says the central issue is that the teaching grant is to be cut by 80% and that the burden will transfer to students.
While he initially thought a graduate tax was a reasonable solution, Mr Cable says he ruled it out after listening to independent analysis that it was "unworkable".
A little under 25% of all graduates will pay less than under the system inherited from Labour, Mr Cable says.
The proposals arouse very strong feelings, inside and outside the House, says the business secretary.
So, Vince Cable is on his feet in the Commons and the debate is under way.
One student preparing to join the London march tells the BBC why she is angry: "So many people I know voted for the Lib Dems because of the fees [policy] and now they're going to increase them."
While London is the focus of today's student protests, demonstrations are going on across the country. Already under way are those at Swansea, Cardiff and Brighton.
MPs are due to kick off the tuition fee debate in the next few minutes.
Students are gathering in Trafalgar Square with placards. "I hope there's no violence but there might be later on," said Rose, 16, a student from Pimlico, attending her fourth anti-fees protest. "It seems as the atmosphere builds the police just lash out at everyone and people just react."
James in London writes: "Increasing numbers of students result in increased costs which the government is unable to pay. The money needs to come from somewhere. Asking those who benefit most as a result of further education is the fairest method of so doing. As such I support the fee increase since it is an investment from which the recipient benefits for the rest of their life."
tweets: "MPs - You can't represent everything by a pound sign and nothing else. Cuts and higher fees are the thin end of the wedge."
Winning the vote will put England's universities on a secure footing, which will be the best outcome for students, adds Mr Willetts. He praises the cohesive nature of the cabinet, which he describes as "two parties working together in the national interest".
David Willetts, the Conservative Higher Education Minister, says he's confident the "vast majority" of the party's MPs will back what he calls a "fair and progressive package".
The BBC's Mike Sergeant says the first students have set off on the march from the University of London Union.
Iain in London writes: "I'm a graduate on the current system and although there are things wrong with it, at least I'm paying it off and should be rid of it in five to 10 years. With these new plans most people will not get anywhere near paying off the full amount and this will end up like a permanant tax on graduates."
BBC News producer Dominic Hurst reports there is a heavy police presence in Whitehall, scene of student violence two weeks ago. Groups of riot police are outside the Treasury, Ministry of Defence and other government buildings. No sign of any protesters yet.
tweets: "Dear Government. You owe me nothing. I owe you nothing. Deal? Thought not."
Shadow education secretary Andy Burnham argues that the government is "about to take a decisive step away from a fair and balanced system" to one that is "stacked against" people from disadvantaged backgrounds.
Lib Dem rebel Greg Mulholland says his amendment proposing to call off the vote to allow for a full public consultation on the future of university funding has not been selected by the Speaker and so MPs will not be able to vote on the proposal.
Dozens of riot police are already around Westminster, some carrying shields. Riot vans have lined up in Bridge Street by Parliament. Crowd barriers are set up near entrances to Parliament, but there are no protesters yet. Clearly police don't want to be caught unawares, reports BBC News producer Dominic Hurst.
Jim writes: "Time to tax all the 'old school' graduates who had free education. Tax them £9000 per year for three years as well so everybody feels the same pain. That is fair."
Shadow education secretary Andy Burnham says today's debate is about the kind of education system needed in England and that the plans will create an "elitist" structure.
tweets: "Going to be an interesting day at demo2010. Police horses warming up and getting riot visors in front of palace. Helicopters buzz above."
Downing Street is staying tight-lipped about the prospects of winning the vote on tuition fees. David Cameron's spokesman says he will not speculate about the result. When asked if there would be any further concessions, he said the government had set out its policy.
Henk de Vries in Hull writes: "The proposals are not unreasonable. If this gets blocked by the Liberal Democrats it may provoke a general election, where Liberal Democrats will lose seats in favour of the Conservatives. The ultimate outcome of tuition fees after that is likely to be worse."
Sally Hunt, from the University and College Union, describes government claims that universities will only charge over £6,000 per year in exceptional circumstances as coming from "fantasy land". The union says institutions will have to charge almost £7,000 to break even.
tweets: "Good luck to all the students and lecturers lobbying their MPs today. LibDem MPs should listen to the people and vote no."
Charlotte Hurrell in Lincoln writes: "While we understand that changes do need to be made to help the country's crisis, this is not the way to do it. The phrase 'mourning the death of education' has been passed around and it certainly is true. This is not only the death of education, it is the death of our nation's professional future."
Students have begun queuing at Portcullis House, opposite the Houses of Parliament, where they intend to lobby MPs, according to reports.
"I'm here to remind my party of the principles and policies I campaigned and voted for," one student wearing a Lib Dem badge at the protest in London tells the BBC.
Jaclyn Horrod in Keynsham writes: "I am paying for a course I want to study. That's fair and right. If I end up making money from my chosen career as a mature student, then that's absolutely fine. Frankly there is no universal right to higher education and the cost of the taxpayer funding the thing is outdated and frankly selfish."
The cabinet meeting is underway and Nick Clegg is there after all, having arrived an hour early, according to the BBC's Laura Kuenssberg outside No 10.
Protesters have started gathering outside the University of London Union, where the march is scheduled to begin in an hour or so.
tweets: "Why do the lecturers who believe in "free education" not forgo their salary and work for nothing?"
Ministers have been filing in to No 10 for today's cabinet meeting, though only after passing the huge Christmas tree which is standing next to the famous black door. No sign of Lib Dem leader Nick Clegg or Business Secretary Vince Cable yet.
tweets: "Good luck to those of you attending the protests today. Keep your fingers crossed!"
Potential rebels have been telling the BBC their plans. Lib Dem Don Foster says he has "genuinely still not decided" how he will vote - and revealed the government was making concessions to backbenchers hours before the vote. Meanwhile, Conservative Peter Bone says he will listen to the debate before making up his mind. "If I think my constituents will be put off going to university, I'll vote against it," he adds.
Hello and welcome to coverage of what's going to be a crucial tuition fees debate and vote. It is due to take place in the Commons throughout the afternoon, during which thousands of students are expected to protest at the plans. Fees at English universities would rise to a maximum of £9,000 per year from 2012.