In the Mori survey for the Financial Times business daily, people were asked whether they agreed with the statement that "it's now time for Tony Blair to resign and hand over to someone else".

Fifty per cent said they agreed, 39 per cent said they disagreed, and 11 per cent said they did not know.

Some 64 per cent said they were dissatisfied with Blair's performance, an all-time high, according to the FT, which said the results illustrated the extent to which he had lost public trust as a result of the Iraq war.

The failure of international inspectors to find weapons of mass destruction following the conflict and the suicide of British weapons expert David Kelly in July have plunged Blair into the worst crisis of his six-year tenure.

Government scientist Kelly was the source of claims reported by the BBC in May that Britain embellished its case for war on Iraq in a government dossier published a year ago.

The Financial Times poll of nearly 2,000 adults, conducted between September 11 and 16, showed that Labour had a nine-point lead over the opposition Conservatives.

When the same voters are asked how they would vote if finance minister Gordon Brown were Labour leader, the party's lead rose from nine points to 15 points.

Meanwhile, a YouGov poll for Saturday's right-wing Daily Telegraph found Labour had been overtaken by the Conservatives.

It put the Tories on 32 per cent, Labour on 31, and the Liberal Democrats, the second biggest opposition party, on 30.