His actions failed to quell a mood of dissent among rank-and-file legislators, or stem a procession of walkouts by once-loyal colleagues. Caroline Flint quit her post as Europe minister
- one of 10 ministers to resign out of 23 - and accused Brown of keeping her as "female window dressing" in a male-dominated Cabinet.
Dissident legislators said a plot to oust Brown could gather pace when expected dismal results in the European Parliament elections are announced Sunday.
"I will not waver. I will not walk away. I will get on with the job," Brown told reporters. He insisted he won't be forced from office and said he can defy all predictions by winning a national election that must be called by June 2010.
Opponents say Brown is tainted by the economic crisis and the expenses scandal, has little authority over his ranks and is so unpopular that his governing Labour Party is doomed to defeat when voters next have a chance to choose a government.
Britain's main opposition Conservative Party routed Brown's party in local elections Thursday, winning council seats in former Labour strongholds in northern and central England.
"I now believe your continued leadership makes a Conservative victory more, not less, likely," Work and Pensions Secretary James Purnell told Brown late Thursday in a letter, quitting his Cabinet post.
Despite his insistence that he can revive Labour's fortunes, analysts said Brown's position as British leader is in serious peril. "I don't see what Brown can do. I think the damage has gone too deep now," said Pete Dorey, a political scientist at the University of Cardiff.
Brown spent much of Friday huddled in a basement office in his official Downing Street residence, shuffling Post-it notes bearing the names of lawmakers as he finalized his Cabinet shake-up.
Outside, results of British local elections showed a collapse in support for his party, which has held power in Britain since 1997. Brown's Labour looked likely to be pushed into third place behind the Conservatives and Liberal Democrats, according to initial results.
He faces an imminent new electoral test after lawmaker Ian Gibson said Friday he would resign from the House of Commons immediately, triggering a special election within weeks. Gibson had been criticized in the expenses scandal.
Brown's government has suffered the most in a scandal over lawmakers' expense claims, blamed for failing to reform a system that allowed legislators from all parties to charge for items such as horse manure, porn movies and repairs to the moat of a country mansion.
"He looks like a wounded animal at the moment," said consultant Lance Doughty, walking by London's Parliament building. "I think it's really tough for him to stay where he is."
Alan Johnson - often mentioned as a replacement for Brown and promoted Thursday to Home secretary
- urged colleagues to unite behind the leader despite the latest election results. "It is vital now, more than ever, that we unite for the sake of the party and the government," he said.
Brown promoted Yvette Cooper, deputy Treasury chief, to a high profile job as Work and Pensions secretary to replace Purnell and drafted the largely unknown Bob Ainsworth to become the new Defense secretary.
Treasury chief Alistair Darling was kept in his post, despite concern over his expenses. Darling repaid some money after acknowledging mistakes in his claims and has faced criticism over his manipulation of the housing allowances.
Foreign Secretary David Miliband and Business Secretary Peter Mandelson also retained their posts.
Alan Sugar, a brash businessman and host of the British version of "The Apprentice" television show, was appointed a member of the House of Lords and given a new role to promote entrepreneurship and help stimulate Britain's economy.
International Development Secretary Douglas Alexander said Labour lawmakers must decide whether to pledge loyalty to Brown and his new team, or support plots to oust him. Lawmakers "have a serious judgment to make in the hours ahead," Alexander told BBC radio.
A group of legislators have mulled collecting signatures to an e-mail statement calling on Brown to resign, but have yet to make their campaign public.
