Harriet Harman: Labour suffered a "very dismal result"
Labour has suffered its worst post-war election result after it was beaten into third place by UKIP and saw the BNP gain its first seats at Brussels.
Labour's share of the vote at the European elections was just 15.3% - worse than party bosses had feared.
The Tories won with 28.6%, beating Labour in Wales but failing to increase their total share significantly.
The results have sent shockwaves through UK politics and led to renewed calls for Gordon Brown to quit as PM.
The BNP gained a seat in Yorkshire and Humberside and in the north west of England, where party leader Nick Griffin was elected - the first time the anti-immigration party has won seats at national elections.
Their result was condemned across the political spectrum, with both the Tories and Labour calling it a "sad day" for British politics.
Health Secretary Andy Burnham said: "The BNP is like the ultimate protest vote. It is how to deliver the establishment a two-fingered salute. I think largely it is a comment on Westminster politics."
It was a long night of painful firsts for the Labour Party
But she backed Gordon Brown saying he was "resilient" and would sort out the economy and expenses.
"What we won't be doing is wringing our hands, being disunited," she said.
Conservative leader David Cameron said he was "delighted" with the results: "The Conservative party were the clear winners in these elections.
"We topped the poll, we increased our share of the vote, increased our number of MEPs, we won in almost every part of the country and had some staggering results like topping the poll in Wales."
'Mocked and derided'
He said taken with last week's local election results it showed "an enormous gap opening up between Labour and Conservative" with the Tories "almost getting twice as many votes as Labour last night".
Other UK-wide Westminster parties effectively trod water on their 2004 European results, with the Lib Dems coming fourth and the Tories increasing their share by just over 1%.
This left the smaller parties to benefit - possibly from public anger over the MP expenses scandal.
Jubilant BNP leader hails 'great victory'
UKIP, which campaigns for Britain's withdrawal from the EU, gained 17.4% of the vote and increased its number of MEPs to 13 - beating Labour into third place.
Leader Nigel Farage said his party's performance was a "hell of an achievement" which sent a clear signal to Gordon Brown.
"He has been beaten by a party that he mocked and derided as being on the fringes - so if we have beaten him, he has got to go," Mr Farage said.
In two English regions, the South-East and South-West, the Green Party beat Labour into fifth place.
Nationally, the Greens increased their share of the vote to 8.7% but leader Caroline Lucas blamed the electoral system for her party's failure to gain more than its current two MEPs.
"In the South East we have increased our vote by 50% and we are disappointed it has not translated into a second seat," Ms Lucas said.
William Hague says the results show "people clearly want change"
The Lib Dems saw their share of the vote shrink slightly on 2004, but leader Nick Clegg told the BBC that taken with last week's local election results, his party had a strong platform to make gains against Labour at a general election.
"On the European vote we held our own, we actually added an MEP - would I have liked to have done even better, yes of course but I think given the very volatile nature of the elections it was a solid result."
He said Labour's 12-year dominance of British politics was over and the party "finished".
In Scotland, SNP leader Alex Salmond hailed a "historic" victory after the Nationalists hammered Labour.
Across Scotland the SNP secured 29% of the vote to Labour's 21%, comfortably achieving the target the SNP leader had set his party at the start of the campaign.
Welsh Labour also suffered humiliation in the European elections, with the Conservatives topping the poll.
If Labour MPs put their terror of the electorate above any considerations of patriotism or democracy, they will do irreparable damage, not just to their party's long-term prospects, but to representative democracy. This is your last chance, comrades.
They look to the government for high quality public services, and a sense of purpose and direction for the country. The prime minister has to articulate that and, sadly, it hasn't happened. Not that there is an alternative on offer from the other main parties.
It needs to be said with great clarity: these results are terminally disastrous for the Labour Party. It is still an open question, however, whether the Labour Party wishes to draw any conclusions from this electoral rout about the future of its leader The next few days could set the course of Labour politics for a generation. If the party decides to stick by Mr Brown it is likely he will lead them to a large defeat. The first years of opposition could be wasted in a war to assign blame But the moment is upon them. The Cabinet risks being written off as a collection of cynics and cowards. It is almost too late.
Boris Johnson says in the Telegraph
that the reason Labour backbenchers aren't revolting against Gordon Brown shows they are more bothered about their own finances than the country:
Now is the moment for all the guilty men and women who claimed for plasma TVs and bath plugs and Peperamis to show that they are willing to put the interests of the country first, jettison Gordon, and have an election. To persist with Gordon is an admission that the cause is lost, and that the best bet is for the maximum number of Labour MPs to hang on to their seats and their dosh for as long as possible
The public mood is clearly for a general election, not because there is great enthusiasm for the opposition (the European results and strength of minor parties shows there is not) but because people think this parliament has no legitimacy.
Labour reached its political nadir this weekend. If, as now seems probable, the worst of the downturn occurred between the ¬collapse of Lehman Brothers in September and the G20 meeting in London in early April, the government at least has a political narrative for voters in the run-up to the election: thanks to our efforts, things are getting better.
Tonight party backbenchers and Peers will decide if it is time to kill off the battered Premier. The PM is preparing to buy them off by promising an Iraq War probe and will shelve plans to sell off the Royal Mail within days... The only real way for Mr Brown to reassert his authority is to hold a general election and win it.
For all his efforts, Mandelson may not save Brown either. Lord Falconer added to the pressure yesterday by calling for a debate over the leadership; tonight, the Parliamentary party might deliver the coup de grace. But a new leader won't save them - and neither will a propped-up Gordon Brown. It's the Labour Government that is the problem; and it's Labour, whether Lord Mandelson and the rest of them realise it or not, whose time is now up.
Labour MPs will return to Westminster today in a very gloomy mood. Their choice is whether to challenge Mr Brown now or to acquiesce, however reluctantly, in the reshuffle and leadership counter-attack. The odds are that the plotters will get nowhere this week and Mr Brown will survive in the short-term. But that will not end the complaints or doubts about his leadership. The European results underline just how unpopular Labour is.
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