The voters have demonstrated their contempt for the war in Iraq

In a welcome departure from the usual post-election script, John Prescott, the Deputy Prime Minister, displayed brutal honesty. Abandoning any attempts at phoney triumphalism, he admitted that the voters had given Labour a "good kicking". Indeed they have; the voters have given Labour its biggest kicking since Tony Blair became leader in 1994. Even Ken Livingstone's victory in London is of limited comfort. The opinion polls in advance of the result all suggested that Mr Livingstone would have won by a wider margin if he had stood as an independent. Mr Livingstone won in spite of the endorsement from Mr Blair, not because of it.

In a welcome departure from the usual post-election script, John Prescott, the Deputy Prime Minister, displayed brutal honesty. Abandoning any attempts at phoney triumphalism, he admitted that the voters had given Labour a "good kicking". Indeed they have; the voters have given Labour its biggest kicking since Tony Blair became leader in 1994. Even Ken Livingstone's victory in London is of limited comfort. The opinion polls in advance of the result all suggested that Mr Livingstone would have won by a wider margin if he had stood as an independent. Mr Livingstone won in spite of the endorsement from Mr Blair, not because of it.

The scale of Labour's losses confirms that the party is being punished for Mr Blair's decision to support the war against Iraq, together with the manner in which he sold the conflict to the public. It was the main excuse of Cabinet ministers as they toured the studios yesterday. All of them repeated the mantra that the elections had taken place in the shadow of the war - which was interesting since, until now, ministers have insisted that the conflict was merely a "Westminster village" obsession. It was good to see some belated honesty on this issue, even if it was forced out by the voters.

If there is one clear message from these elections, it is that politicians are foolish to believe in the gullibility of the electorate. Instead, voters demonstrated that they do not forgive a Prime Minister who takes the country to war on a false premise. Mr Blair hoped voters would "move on" to other issues. Instead, he has had a sharp reminder of the size of his task in regaining the public's trust after his repeated declarations in the build-up to war that Saddam's weapons of mass destruction posed an imminent threat. The key issue now is whether the voters can trust his claims about the Government's domestic record after he has debased his position in this way.

Additionally, Labour should be concerned over the damage to the party's power base in many parts of the country. Party managers should take a long, hard look at what happened when Conservative prime ministers eroded the Tory strongholds in Scotland, the North and the Midlands; the party is still suffering the effects of this today.

By contrast, the Conservatives can take some comfort from last night's results, especially as they were heading for electoral oblivion last autumn under Iain Duncan Smith. Michael Howard's leadership has given them a fresh credibility and impetus, and they have begun to claw back some of that lost ground. However, on any realistic assessment, the general election winning post remains some distance over the horizon.

Mr Howard, who wisely resisted the temptation to make grandiose claims on the back of these results, should enjoy the weekend. Late on Sunday evening, when the European election results are revealed, he will have rather more awkward questions to answer on the issue that has tormented his party for two decades. Polls suggest the UK Independence Party has seduced a significant number of traditional Tory voters; already there are signs of renewed divisions within the Conservatives over how to respond to this threat.

The Liberal Democrats are the main beneficiaries of this disillusionment over Mr Blair's support for war. Having taken a courageous stance on this conflict, they deserved their spectacular gains. No wonder Charles Kennedy chose to make an appearance in Newcastle yesterday. Labour ruled the city with a big majority even during the party's darkest days in the 1980s; this morning, it is under Liberal Democrat control.

Mr Kennedy, however, cannot be too euphoric. His party made gains largely at the expense of Labour. At a general election, the Liberal Demo-crats' main targets will be Conservative seats. But they did much less well in Tory strongholds and in some cases the Conservatives made gains at their expense. This continues to be the dilemma for a third party within a two-party system.

With a higher turnout than expected, there were encouraging signs that voters made intelligent use of the choices available to them. The Greens performed well, especially in London, while the loathsome BNP did not make much progress. The indications are that voters were comfortable with the range of choices and elections on offer, tailoring their votes in a sophisticated manner.

The big question, of course, is whether the electorate, dismayed by Mr Blair's behaviour on the international stage, has delivered a shot across his bows or registered a more permanent loss of faith. Mr Blair's ill-judged alliance with President Bush was based partly on the calculation that Labour-supporting opponents of the war would have nowhere else to go. The voters have shown this is not the case; Mr Blair, having abused their trust, has a tough challenge to bring them back into the fold before the general election.

This is half time in the biggest electoral test before the general election. The final score will not be clear until Sunday evening. But, as matters stand, Mr Blair can no longer claim to be the great vote winner for his party. This is a dangerous position for him to be in - and he can no longer delude himself over the depth of the public's distaste for his foreign adventurism.