‘‘There is one overriding question for my colleagues and that is, who is best placed to defeat Tony Abbott at the next election,’’ he said.

‘‘Mr Abbott, I believe, does not have the temperament or the experience to ever be elected and hold the office – the high office – of Prime Minister of Australia, but at present, and for a long time now, he’s been on track just to do that.’’

Mr Rudd said in Washington at 1.20am local time he had no option but to leave Cabinet because he did not have the support of the Prime Minister.

Mr Rudd is furious that Ms Gillard appeared to allow senior ministers to attack him, with no repudiation from her.

The attacks intensified last night, as Treasurer Wayne Swan said Mr Rudd had put his self-interest ahead of the interests of the broader labour movement and the country as a whole.

‘‘The party has given Kevin Rudd all the opportunities in the world and he wasted them with his dysfunctional decision making and his deeply demeaning attitude towards other people including our caucus colleagues,’’ Mr Swan said.

‘‘He sought to tear down the 2010 campaign, deliberately risking an Abbott prime ministership, and now he undermines the government at every turn.’’

Environment Minister Tony Burke launched a scathing fightback against Mr Rudd last night, accusing the former foreign minister of conducting a ‘‘stealth and undermining campaign for a very long time’’.

‘‘The fact that Kevin has been openly campaigning for the leadership has been the worst-kept secret in Canberra,’’ he said.

He revealed that Ms Gillard’s inner circle believed the campaign would ‘‘go away naturally’’ because support for Mr Rudd was declining.

Earlier yesterday, senior government figures had stepped up their pressure on Ms Gillard to sack Mr Rudd for disloyalty or call on a leadership ballot at next Tuesday’s scheduled caucus meeting.

Climate Change Minister Greg Combet said the row had to be resolved very quickly.

Earlier yesterday, Mr Rudd had said he supported the Prime Minister and ‘‘intended’’ to remain as foreign minister’’.

One of his key backers said last night Mr Rudd was not prepared to stay overseas and ‘‘be kicked’’ by cabinet colleagues.

Mr Rudd conceded the ‘‘soap opera’’ was damaging the state election campaign of his fellow Queenslander, Premier Anna Bligh.

‘‘I cannot continue to serve as foreign minister if I do not have the Prime Minister’s support and so I have decided to do the honourable thing and the honourable thing is to resign,’’ he said.

‘‘There is no way I will ever be party to a stealth attack on a sitting prime minister who was elected by the people. We all know that what happened then was wrong and it must never happen again.’’

He said the reign of ‘‘faceless men’’ and their iron grip on the control of the Labor leadership must end.

Mr Rudd confirmed the Prime Minister’s failure to repudiate Simon Crean and other cabinet ministers’ attacks on him throughout the week had been central to his decision to resign as foreign minister.

‘‘The truth is I can only serve as foreign minister if I have the confidence of Prime Minister Gillard and her senior ministers.

‘‘In recent days Mr [Simon] Crean and a number of other faceless men have publicly attacked my integrity and therefore my fitness to serve as a minister in the government.

‘‘When challenged today on these attacks Prime Minister Gillard chose not to repudiate them. I can only reluctantly conclude that she therefore shares these views.’’

Mr Rudd said he was sad to leave the office. It was the second time he had resigned from high office – the first as prime minister after the 2010 leadership coup – and that the two events shared similarities.