Analysis: Brown emerges stronger | Comment Central: the reshuffle - live! | James Purnell quits | The resignation letter | Latest from the elections

Labour's civil war got personal tonight as the last of a string of ministers to quit Gordon Brown's front bench accused him of running a "two-tier government".

The parting shot from Caroline Flint, the Europe Minister, came even as Mr Brown held a press conference to unveil his reshuffled Cabinet and relaunch his premiership.

As he spoke she sent out a resignation letter in which she accused Mr Brown of surrounding himself with cronies. "Several of the women attending Cabinet - myself included - have been treated by you as little more than female window dressing," she added.

Ms Flint was the sixth senior minister to stand down in the past four days, and the third today, as Mr Brown struggled to complete a Cabinet reshuffle from a pool of talent that seemed to be draining away by the hour.

Last night's abrupt resignation of James Purnell - who called for the Prime Minister to stand down for the good of the party - saw a closing of Cabinet ranks this morning that augured well for the Prime Minister's ability to reassert his authority.

But the Blairite John Hutton resigned as Defence Secretary this morning after deciding to retire from frontline politics and this afternoon it emerged that Mr Hoon, a Cabinet veteran, was also standing down from the Department of Transport.

Ms Flint is a friend and ally of Hazel Blears and Jacqui Smith, who resigned last week, but she had remained loyal to Mr Brown and clearly expected to be rewarded for it. Instead, she complained, she found herself the target of hostile briefings alleging that she had been part of a plot against the Prime Minister.

She wrote: "Time and time again I have stepped before the cameras to sincerely defend your reputation in the interests of the Labour Party and the Government as a whole. I am a natural party loyalist. Yet you have strained every sinew of that loyalty.

"It has been apparent for some time that you do not see me playing a more influential role in the Government. Therefore, I have respectfully declined your offer to continue in the Government as Minister for Europe attending Cabinet."

The flurry of departures, which also included Paul Murphy, the Welsh Secretary, meant that Mr Brown was unable to impose his personal stamp on his new frontbench line-up.

As a result, Mr Brown was forced to keep Alistair Darling at the Treasury - he had hoped to replace him with his old friend Ed Balls - and to promote Alan Johnson, the favourite to succeed him, to replace Jacqui Smith at the Home Office.