But BBC political correspondent James Landale said MPs, crammed into the committee room, cheered and banged desks in support of the prime minister.
Defence Secretary Bob Ainsworth said there had been "no support" for the rebels who spoke and the meeting had been "overwhelmingly" supportive of the prime minister.
According to his spokesman, Mr Brown told the room he had "strengths and weaknesses" and that there were "some things I do well and some things not so well".
Another ex-home secretary, David Blunkett, also told the meeting the rebels should "put up or shut up", the BBC has been told.
Backbencher Barry Sheerman - who had previously called for a debate on the leadership - said he had expressed his own reservations about Mr Brown, but had been won over by his pledge to consult more and be more transparent.
Mr Sheerman added: "If the prime minister sticks to what he says, those of us who have been his critics will stand down for the time being."
Ever since James Purnell's dramatic resignation from the cabinet there has been what one of those working to unseat the prime minister describes as "a battle of the bodies".
Conservative leader David Cameron said Mr Brown and his critics were locked in "a slow dance of political death".
"He can't seem to reshuffle his cabinet but they can't seem to organise a coup," he told Tory activists in Wales - where the Conservatives pushed Labour into second place in the European elections.
A ComRes survey for the Independent suggests Alan Johnson would cut Mr Cameron's advantage if the new home secretary were to become Labour leader.
It said the Tories would lead by 38% to 22% with Mr Brown at Downing Street, but with Mr Johnson at the helm Labour's support would rise to 26% and backing for David Cameron would fall to 36% - enough to deny the Conservatives an overall majority.
Mr Brown has been reshuffling his junior ministers, following last week's cabinet reshuffle and departure of six cabinet ministers and several other ministers.
Part of that process has seen the departure of Ms Kennedy, Liverpool Wavertree MP, who has quit the government before - as health minister in 2006 over NHS reforms.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.