These election results leave the Prime Minister with no option but to argue the case for Europe

Across the continent, Europeans have registered a massive vote of no confidence in governments they themselves elected, sometimes only a matter of months ago. From London, through Paris, Rome, Berlin and Warsaw, the message resounds loud and clear: a plague on all your houses. Whatever the political complexion of the government, its stance on Iraq, its economic performance or its professed social objectives, a large majority of those casting a vote chose to use it in protest against the party, or the people, in power.

In one way, this is an entirely acceptable use of the ballot box. Give voters a chance, in the middle of a government's term, and they are likely to voice objections. In another way, however, the results demonstrate just how remote the European project remains to most voters. In elections for a new European Parliament - a body whose authority and influence is growing, while that of other European institutions wanes - voters focused almost exclusively on national issues. They saw their votes less as a contribution to democracy in Europe than as a chance to fire a warning across the bows of their own government.

Not all voters cared enough even to register a protest. The turn-out almost everywhere was down compared with five years ago, although Britain was an honourable exception. The turn-out in most of the "new" European countries was especially disappointing in the light of their enthusiasm to join the European Union in the first place. The kindest explanation is that, after a decade of free elections and having achieved their goal of EU membership, they are suffering from election fatigue.

Where voters cared enough to vote, however, they cared in a predominantly negative way, and nowhere was this clearer or more depressing than here in Britain, where the European elections unleashed all the old demons of insular anti-Europeanism. In the newly energised UK Independence Party, those opposed to Europe found an outlet for their hostility. Perversely, the one nation that actually voted on a European issue in the Euro elections was the one that is most viscerally anti-European.

The only consolation is that we pro-Europeans now know what we are up against. We know that, given the choice, almost one in five voters would currently support Britain's withdrawal from the European Union altogether. More than one in four (the Tory vote) take a sceptical view of Britain's EU membership. This leaves the less than 40 per cent of the vote shared by Labour and the Liberal Democrats as the measure of British voters' support for Europe. In other words, this country remains as divided about Europe as ever it was.

While the implications of the protest for most other European governments are unambiguous - the electorate does not particularly like what is being done in its name, but has little choice but to lump it until the next general election - the consequences for the British Government, and for Mr Blair personally, are far more serious. The Euro election results were the second drubbing for the Government within a week. Labour lost almost 500 seats at the local elections and control of nine councils, including cities where its sway had long been taken for granted. After months of pretending that the Iraq war was not a factor, ministers finally came clean and admitted what their candidates had been hearing on the doorstep: that they were furious with Labour, and with Tony Blair, because of Iraq.

The Iraq war may have been less of a factor in the Euro elections, but it certainly offered no recommendation to waverers considering a Labour vote. And while Labour ministers insisted yesterday that the results of the European vote were far worse for the Tories than for Labour, they were either deluding themselves or being deliberately disingenuous. Certainly, the Tory vote fell by 9 per cent compared with five years ago. But the Tory vote then was unexpectedly high, and the Tories were always going to suffer more from the UKIP effect than any other party. In fact, UKIP and Iraq together seem to have taken a sizeable chunk out of Labour's Euro vote, too. Labour could, and should, have attracted far more support than it did.

The Prime Minister now finds himself caught in a double trap of his own making, which entwines the vexed question of Europe and his own prospects at the next general election. While most UKIP votes will return to the Tories at the next general election, Mr Blair cannot be so confident of retrieving Labour defectors. His clear hope had been to push all quarrelling about Europe off the agenda with his promise to hold a referendum. If the European constitution is agreed next week, the referendum promise will return to haunt him at the very time when the chance of a "yes" vote looks bleaker than ever. Whether on the narrow question of the EU constitution, or the broader one of staying in Europe, the Euro elections have shown British voters to be as negatively disposed as ever. Nor, after the Iraq débâcle, are they inclined to do the Prime Minister any favours.

Such a time calls for boldness. Mr Blair needs to throw caution to the wind and fight. To look on the brightest side of the European election results, the British public is not yet completely lost to the European cause. UKIP took 17 per cent of the vote, not 20 per cent, nor 30. This is the extent of diehard anti-European sentiment in this country. There are pro-Europeans among Tories, though they keep themselves well camouflaged, and more than 50 per cent of the electorate did not feel strongly enough either way to cast a vote. There are votes out there going begging. If he summoned up all his old gifts of persuasion, Mr Blair could yet realise his ambition to reconcile Britain with Europe.