The prime minister has secured a marked increase in public support following the war in Iraq.

Almost half of the electorate now believe Tony Blair is doing a good job as prime minister, giving the Labour leader a seven point approval rating, according to the latest poll.

The public relief over the quick resolution of the war demonstrates a marked turnaround from a position of extreme vulnerability just two months ago.

His 49 per cent satisfaction rating outstrips the 42 per cent of the public who are unhappy with his work.

This seven point approval rating compares favourably with the net figure of minus 20 per cent in February.

It also contrasts starkly with the minus 17 per cent rating for Conservative leader Iain Duncan Smith who, despite his support, enjoys little of the "Baghdad bounce" awarded to Blair.

Charles Kennedy, who opposed military action but backed British troops once they were deployed, still enjoys the highest rating among the major party leaders at 14 points - down from a high of 21 points in February.

ICM's poll for the Guardian was undertaken between Thursday and Saturday last week, allowing the Budget and the fall of Saddam Hussein time to impact upon public opinion.

Researchers also found that 42 per cent of the electorate would vote for Labour in a general election, up four points from March.

This compares to 30 per cent for the Conservatives, who fall two points, and 21 per cent for the Liberal Democrats, who drop three.

But with Labour supporters less likely to vote in the local elections, the poll lead may not translate into such a respectable performance at the ballot box next Thursday.

Labour strategists are expecting heavy blows as their party activists voice mid-term frustration at a failure to get their vote out.

Conservative sources are also predicting a marginal improvement in party fortunes.

But while many experts believe the Liberal Democrats will be the main beneficiaries, they also suspect that the Tories may be deliberately underplaying expectations in order to protect Duncan Smith against a summer leadership challenge.

ICM found that Conservative voters were more likely to cast their ballot than supporters of other parties.

Only 52 per cent of Labour voters say that they will definitely vote next week, compared to 57 per cent of Lib Dems and 62 per cent of Tories.