Tony Blair will dismiss calls by allies of Gordon Brown to announce a firm departure timetable after Labour's expected drubbing in today's local elections.
Ministers backing the Chancellor warned that demands for a timetable for the Prime Minister to hand over the reins of power would become unstoppable. Labour is resigned to coming an embarrassing third place behind the Tories and Liberal Democrats in the parties' share of the vote.
Mr Blair will try to restore his authority by reshuffling his Cabinet after his Government was blown off course by the release of foreign criminals, NHS job cuts, the "cash for honours" scandal and the disclosure of John Prescott's affair with his diary secretary.
The ministerial shake-up, almost certainly Mr Blair's last, is expected on Monday.
Senior Labour figures including John Prescott, the Deputy Prime Minister, fear an outbreak of civil war between Blairites and Brownites after the elections.
One supporter of the Chancellor said: "There are demands by ministers right across the board, and by backbench Labour MPs for a timetable."
A left-winger added: "We are heading for a meltdown and a timetable is the minimum. This isn't about Clarke or Prescott. It's about Blair."
A senior cabinet minister said: "The Prescott sex scandal is pretty marginal. What is doing us damage is the impression of incompetence."
But allies of Mr Blair said last night that he would be "mad" to disclose when he might leave Downing Street since that would leave him as a lame-duck Prime Minister. "He is firmly of the view that he will not reopen this debate," said one aide. "It would achieve nothing - except to create another load of problems."
The troubles have overshadowed Labour's election campaign and party officials fear Labour could lose up to 400 seats - their "worst-case scenario". They admit plans to fight on local issues have been scuppered by the crises.
Labour fears a poor showing in the key battleground of London, where all 1,861 seats on the 32 borough councils are being contested. "We are going to be slaughtered in London," said one minister involved in the campaign.
Despite Labour's financial problems, more than £1m has been poured into the party's campaign in the capital to hire workers and use more glossy leaflets.
"A lot of good people are going to lose because of the cabinet ministers involved in these scandals," said a minister. "It's such a terrible waste."
Some Blair loyalists are furious with Charles Clarke, Patricia Hewitt and Mr Prescott for the disastrous run-up to the elections. The Deputy Prime Minister was absent from the Commons chamber yesterday for Prime Minister's Questions and turned down a Radio 4 Today interview, despite repeated promises by Labour that he would play a full part in the campaign.
On the eve of the elections, Mr Blair put on a show of unity with Mr Brown when they visited Tooting and Mitcham football club in the marginal borough of Merton, south London. It was their first appearance together since the party's campaign was launched four weeks ago.
The Chancellor insisted: "The case for voting Labour is stronger than ever." He said that the Tories and Liberal Democrats would put Labour's investment in public services at risk.
Mr Brown yesterday declined to discuss the speculation that a poor result would lead to pressure for Mr Blair to make clear when he would hand over the premiership to him. "We are talking about local elections tomorrow," he said. "I think our Labour MPs and Labour councillors want to maximise the Labour vote tomorrow and we are not going to be diverted from that over the next few hours."
Mr Blair said that massive investment in public services was only possible because of Mr Brown's stewardship of the economy and contrasted the Chancellor's "magnificent" record with that of the Conservatives. "You heard a lot of talk last week about Black Wednesday," he said.
"Let me tell you, the real Black Wednesday was when interest rates went up 6 per cent in a day, when families lost their homes, when people lost their jobs, when the whole economic policy of the Government collapsed."
Comments