Tony Blair ruled out setting a timetable for leaving office as prime minister despite his party's disastrous local election results, arguing Monday that he still has a mandate from voters who awarded him a third term last year.

Blair defied critics in his own party demanding he offer a systematic plan to hand over power to the next Labour leader -- even as he repeated promises to stand aside before the next election.

"To state a timetable would simply paralyze the proper working of government, put at risk the necessary changes we are making for Britain and therefore damage the country. It wouldn't end this distraction but merely take it to a new level," Blair said at his monthly news conference.

CountryWatch: United Kingdom

Later in the day he was to face what may be a tense meeting with Labour members of the House of Commons, where some were likely to press again for a timetable for his departure.

Senior allies of the prime minister urged party members to be calm following Labour's third-place showing in English local elections last week and a wide-ranging shake-up of Blair's Cabinet.

Some Labour lawmakers were circulating a draft letter calling for Blair to set a date for stepping down, a legislator from the party told The Associated Press on condition of anonymity.

Blair said he believed some of his critics were simply concerned to insure that there was a smooth transition to a new leader, widely expected to be Treasury chief Gordon Brown.

Others, he warned, have more damaging motives.

"There are also those whose desire is to change radically the direction of policy and not to renew New Labour but to reverse it," Blair said of his persistent critics on the left of the party.

"That way lies not a fourth term victory, but defeat and a return to opposition, and I will fight that all the way.

"I have said that there will be a stable and orderly transition to a new leader. I will see that this is done, because it is in the interests of this country. But it is also in the interests of this country that we get on with the business of governing."

Blair said Brown remains his choice to succeed him as prime minister.

The Labour Party ran third in the English local elections, roughly as bad as it did in local elections in 2004, a year before Blair led the party to its third straight national victory.

The opposition Conservative Party -- energized by its first-place performance in the local vote -- sought to capitalize on Labour's internal divisions.

"This is a state of civil war at the highest levels of government," said Tory leader David Cameron, who leads the strongest opposition Blair has faced since he took office in 1997.

"They are incompetent ... running out of steam, running out of ideas, divided from top to bottom," Cameron said of the government.

The elections followed a dismal period for the government, which has admitted it allowed more than 1,000 foreign criminals to be released at the end of their sentences without considering deportation. The government was also embarrassed by Deputy Prime Minister John Prescott's admission of an extramarital affair with a secretary in his department.

On Friday, Blair fired Charles Clarke as head of the Home Office, which was responsible for the prisoners; he demoted Foreign SecretaryJack Straw to leader of the House of Commons, and stripped Prescott of most of his departmental responsibilities -- including local planning issues -- in the government.

Blair told reporters that the prisoner issue "did us significant damage."

"Given the absolute pummeling we were given in the last two-three weeks, many people were expecting a worse result."