Welcome to Reality Check. Today I'm scrutinising the Liberal Democrats' tax proposals and asking who wins and who loses?
The Liberal Democrats may be only the third largest party at Westminster - but they've got by far the most ambitious tax and spending plans.
At the heart of their proposals is a plan to raise an extra £17bn in taxes - as much as Labour wants to raise over the next five years.
But they don't want to spend any of that money on reducing the deficit. They want to give it back to everyone in Britain who now pays tax by raising the personal allowance - the amount on which you don't pay any income tax - to £10,000.
Their plans raise two big questions. First, can it be done? Second, who wins and who loses?
Both are difficult to answer - especially the second. But through the course of the day, we've given it our best shot.
Here are some early conclusions.
The first is that raising £17bn in extra taxes won't go unnoticed. And they won't be felt only by the very rich.
For example, they want to raise an extra £1.9bn from capital gains tax, by cutting the annual allowance for capital gains from £10,000 to £1,000.
That means anyone who has a capital gain in a single year of more than £1,000 will have to pay tax on it at their marginal rate.
Party officials point out that low earners who have a capital gain of more than £1,000 in a given year may still escape extra tax, thanks to the higher personal allowance.
However, you won't have to be a millionaire to pay more: Anyone who has a second home in the UK or abroad, or a buy-to-let property, or stocks and bonds whose value goes up more than £1,000 in a year, will have to pay more capital gains tax.
Yes, the higher £10,000 personal allowance will offset some of that tax rise.
The point is just that, when you think about how nice it would be to not pay tax on the first £10,000 of your income, you need to remember that, in many cases, they'll be raising the tax on other parts of your income to pay for it.
Here are some of the other big issues with the Liberal Democrats' plans which I'll be getting into.
On winners and losers - do the poorest really gain?
According to the Institute for Fiscal Studies (IFS), the poorest fifth of households will include those with incomes too low to pay income tax. In any given year, one third of adults do not pay income tax and one quarter of adults live in a family where no-one pays income tax.
By definition, those households wouldn't benefit from the higher personal allowance. The biggest gainers from that change would be households where both adults work, and earn less than £100,000 (as now, the higher personal allowance is going to be tapered away after earnings reach that level).
Giving and taking away
But once again, those gains need to be set against the tax increases which will affect millions of earners.
Around three million people pay higher rate tax. Under the Liberal Democrats' plans to limit tax relief on pension contributions to the basic rate, anybody in that tax bracket would either face a lower pension in retirement, or a smaller net income.
This would depend on whether they continued to pay in the same amount, or avoided the hit to their net income by cutting back.
Who would lose from the other big tax changes - like the mansion tax on houses worth more than £2m?
And can they really raise a whopping £4.6bn from cracking down on tax avoidance, when the Treasury's been trying to tackle it for years?
Predictably, experts are questioning whether all of that money could be raised as easily as party officials suggest.
Lib Dem David Laws says people know a 'massive tax giveaway' is not possible
Some - like the cut in pension tax relief - would probably raise roughly what they expect.
Indeed, if people change their behaviour - contribute less to their pension - as a result of these changes, they could raise even more than the £5.4bn they suggest.
That's because people will then be paying a 40% cent tax on that money, not the 20% they would pay if it was going into the pension.
That, incidentally, is why many experts would say it's not very fair to give higher rate taxpayers only basic rate relief.
Remember they will be taxed on that money, years from now, when they receive it as their pension - quite possibly at the higher rate. This change would mean the money was taxed twice - once on the way and once on the way out.
This is the IFS's view of some of the other tax changes: "Their estimates for the mansion tax, the bank tax and the restriction of pensions tax relief do not seem unduly optimistic, while the reforms to capital gains tax would probably raise substantially more than the £1.9bn they suggest. But there is a great deal of uncertainty around all these costings, given the paucity of relevant data available."
It is less kind about the £4.6bn which could be gained from avoidance measures - describing it as "highly speculative".
But probably a bigger question, for voters, will be who gains - and who loses. The answer is it is impossible to say, but it would be foolish to think that only very high earners will lose out.
The manifesto says that "most taxpayers" will see their income tax bill fall by £700 a year. But there is plenty that this calculation leaves out.
Stuart Adam says the Lib Dems are looking at taxes in a 'slightly misleading way'
The Liberal Democrats would be charging capital gains on every gain over £1,000. It's worth noting that for all incomes over £10,000, the rate at which capital gains are taxed would go up as well, from 18% to 20% - or 40% or 50%, depending on the individual's income.
But in any given year, one in four adults live in households that don't pay tax. That's 11 million people who would not benefit at all.
In addition, anyone over 65 will gain very little, because their personal allowance is nearly £10,000 a year now.
Remember that every penny of that tax cut is being paid for out of higher taxes elsewhere, many of them not directly targeted at the well-off.
Out of the original £17bn, we know that £5.45bn is due to come from higher rate taxpayers, via the cut in pension tax relief.
If they raise that much, that would mean an average tax rise of about £1,800 per person, though the rise would be much smaller for people whose incomes are at the lower end of the higher-rate spectrum.
For example, someone who earns £50,000 a year who pays 4% into their pension might pay an extra £400 a year in tax if they carried on as before.
But even that is more than half of the £700 gain from the change in the allowance.
There's another £1.7bn from the 1% levy on properties worth more than £2m. Though there will be exceptions, it's a fair bet that most people who own houses worth more than £2m will be among the upper half of tax payers by income.
So, that £7.1bn would be raised directly from higher earners. But that's less than half of the total. It is impossible to say who would actually end up paying the remaining £10bn.
The bottom line?
Much of the increase in capital gains will also, presumably, be paid by richer households, but - as the example suggests - by no means all.
Anyone with a buy-to-let property or a nest egg that is subject to tax is likely to end up paying more in capital gains. And it wouldn't take a lot to wipe out that £700 gain from the higher allowance.
The £3bn to be raised from taxing aviation would push up the cost of air travel for everyone. That's the intention.
And if they do raise £4.6bn from anti-avoidance - remember that someone, somewhere will ultimately pay that higher tax. If it's a company, that somebody could be its customers, paying higher prices - or employees, getting smaller pay rises. To coin a phrase, companies are people too.
The bottom line is that plans are ambitious. And they would raise a lot of money from the highest earners. But many of the poorest in UK society wouldn't gain. And it will be difficult, if not impossible, for any voter to work out what, exactly, would be in it for them.
A selection of your comments is below.
Everyone will have to raise taxes, voting Tory isn't going to prevent that. Lib Dems have just been honest about where the tax rises will come from initially. Steve, Cookstown
Well it was not a surprise, but it doesn't benefit the poorest or anyone else.. gimmick! Here you don't pay tax on the first £10,000.. sounds cool. But you pay a lot more on the money you earn over £10,000... ahem?? Sounds like Vince Cable has borrowed Brown's book of economic cons 1997, 2001 and 2005 reprints and all! Jon, Gillingham
The Lib Dems aren't going to form the next government so they can put what they like into their manifesto, it's just a waste of trees. Their tax plans are just shifting deckchairs, we need to kick start the economy and get people into work and paying taxes not relying on benefits. Martin, Pontypridd
Let's not forget that Clegg didn't rule out raising VAT after the election. Which means all three parties have refused to rule it out. I think we can all guess which way the VAT rate will be going after the election. Adam, Guildford
Let's face it, we're all going to be hit one way or another over the next five years. We should at least give the Lib Dems the credit for giving us an honest and worked-through appraisal of how they would deal with the deficit. I'd rather have that, than vote for a party who can show me no more than a finger in the air waiting for the oncoming hurricane. Graham, Surrey
Once again we have a really ambitious but pointless manifesto from the Lib Dems, their plans are so large that if they were to get into power and make these changes, the instability caused in the country would be enormous. As for clamping down on Tax Avoidance, Gordon Brown has closed most tax avoidance schemes down anyway, I doubt they could do much more without seriously harming the country. Chris, Neath
I guess the taxes will only seem fair if you are set to gain. The Lib Dems local income tax would severely hit many people in their late 20s/early 30s who have just about reached a position to enter the housing market (income rich, asset poor), who would be forced to subsidise retired people who already own their properties (income poor, asset rich). Richard, Southampton
The critical point here is that the Lib Dems are confident enough in their figures, within a sensible margin of error, to publish them in their manifesto with far greater detail than any other party. If we're going to do reality check on tax plans, lets make sure we give fair attention to those parties that have so few figures that it's impossible to check their plausibility. John, Bristol
Surely abolishing higher rate tax relief on pensions will be the nail in the coffin of final salary schemes in the private sector? People running companies will no longer have any personal incentive to contribute and with deficits etc will just shut them. Benedict, Surrey
So, if you had quotes from three builders, one said "We'll do what we did last time and tell you how much it is when you decide to hire us", the second said "We're not exactly sure how much this will all cost but would you mind mucking in to help us occasionally" and third said "It costs this and this and this". Seriously. Who would you hire? Jason, London
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