Tony Blair's greatest task in the wake of his local and European election humilliations will be to persuade his MPs not to panic.
By Nick Assinder
BBC News Online political correspondent
If the prime minister is to survive these disasters he must head off any suggestions that he was personally responsible for them.
Mr Blair is to start negotiations on the EU constitution
If Labour MPs look at these results, then extrapolate to the next general election and see their parliamentary seats at risk, things could get very ugly indeed for the prime minister.
The breakthrough by the UK Independence Party in the Euro poll provided a temporary distraction from Mr Blair's problems as the Tories suffered worst at the hands of the anti-EU group.
And it was pretty plain that voters were delivering a kicking to all the main "traditional" parties by turning to all the smaller parties, suggesting there is an unusually volatile electorate at the moment.
But, while Mr Blair will attempt to emphasis the Tories' drubbing by UKIP and its good, but not quite good enough, local election performance, attention will quickly turn back to him.
And that will inevitably increase the pressure on his leadership - an issue which looks set to dominate politics for some time to come.
The Euro elections may be quickly discounted as a one off - although all the parties will suffer if they fail to take account of the powerful anti-EU voice in the country.
Robert Kilroy Silk's party may have caused a major upset, but few believe they will go on to repeat that at the general election. Just ask the Greens who were in a very similar position some 15 years ago.
Counting is happening across Europe
But that may not help Mr Blair as UKIP took more votes from the Tories than Labour, suggesting those voters would return to their natural homes at the general election.
The result will certainly give the Eurosceptics a powerful new voice in the European Parliament - if they choose to work together - at a crunch time for the development of the newly-enlarged EU.
And there will be an almost immediate test of the new mood on Thursday when EU leaders meet in Brussels to hammer out the final draft of the planned EU constitution.
Put to test
Tony Blair will travel to that summit knowing that, in Britain and elsewhere, there is a substantial proportion of the electorate which wants out of the entire EU project.
It has been argued he will be quite happy with that as it will allow him to demand more concessions from his EU partners and combat any federalist tendencies.
But he will be far less happy with the overall result of these elections.
His chances of winning the referendum on the constitution must have slipped even further.
Gordon Brown urges Labour to listen to voters
And his pledge to go out and publicly argue the pro-European case will have to be put to the test.
But potentially far worse would be any suggestion that the public has had enough of Tony Blair.
Protests over the war on Iraq and a general breakdown in trust of the government appears to have played a major part in Labour's disastrous polling.
The prime minister has already talked about keeping his nerve and carrying on with the tasks at hand.
But the critics within his party will want to see concrete changes.
They will need reassuring that Mr Blair will not lead them into a similar disaster at the next general election.
And the possibility that they will come to the conclusion that their chances of re-election may be better under a different leader, such as Gordon Brown, cannot be entirely ruled out.
Mr Blair will be able to argue away the European parlaiment election and take some comfort from the Tory result.
He may find it far harder to dismiss the poor showing he suffered in the local elections.