A defiant Gordon Brown vowed Friday to tough it out as Britain's prime minister after Cabinet members quit in bitter circumstances and his governing Labour Party suffered electoral meltdown. “I will not waver, I will not walk away... I will get on with the job,” Brown told a news conference after announcing a swift but limited cabinet reshuffle in a bid to stem the haemorrhaging of authority in his position. The shake-up, originally expected next week, was brought forward after four Cabinet ministers quit within 24 hours -- taking the total number of ministerial resignations in the past week to 10. James Purnell delivered a withering call for Brown to stand down or lead Labour to disaster at the next general election as he quit as work and pensions secretary. The resignations of defence secretary John Hutton, transport secretary Geoff Hoon and Welsh secretary Paul Murphy followed hours later. Then Europe minister Caroline Flint quit -- during Brown's press conference -- with an extraordinary attack on the prime minister. She accused him of using her and other women as “female window dressing” and running a “two-tier” government with an “inner” Cabinet circle. In his resignation letter late Thursday, Purnell said: “Your continued leadership makes a Conservative victory more, not less, likely. That would be disastrous for our country.” “I am therefore calling on you to stand aside to give our party a fighting chance of winning.” David Cameron, leader of the main opposition Conservatives, said Friday's events showed the government was “completely falling apart.” “He is not reshuffling the cabinet, the cabinet is reshuffling him,” Cameron said of Brown. “The argument for a general election has always been strong; now it is unanswerable.” A national vote must be held by the middle of next year at the latest. In his news conference, Brown acknowledged the damage caused by a scandal over lawmakers' expenses and admitted his party was in line for a “painful defeat” after English local and European parliamentary elections held Thursday.