Last night Mr Rudd resigned suddenly as Foreign Affairs Minister while on business in Washington DC, paving the way for an urgent leadership vote in the ALP Caucus this Monday.

Prime Minister Julia Gillard is expected to confirm today a leadership challenge will take place on Monday when MPs return to Canberra.

However, NSW Labor Senator Doug Cameron said Ms Gillard would be unable to lead the party to victory at the next Federal election.

He said Mr Rudd could win a caucus ballot but it would be challenging.

If Mr Rudd was to lose the vote he may be expected to resign to save face, triggering a by-election in his QLD electorate.

Given the government’s persistent poor polling results and a likely backlash against Labor for its seemingly harsh treatment of Mr Rudd who is popular in QLD, the Coalition could perceivably claim the seat.

That victory would return the House of Representative’s numbers to the same position they were in after the 2010 election when key rural independents Tony Windsor, Rob Oakeshott and Bob Katter effectively decided the government’s fate.

Those numbers were altered late last year when Harry Jenkins stepped down from the speaker’s chair and returned to the backbench, while Peter Slipper quit the Liberal party to become an independent and assumed the speaker’s chair.

That gave the Gillard government one more vote and took one off the Coalition, which also gave the independents less sway.

New England MP Tony Windsor said his agreement to form government after the 2010 election was made with Ms Gillard and not Mr Rudd.

He indicated that if there was a change of Labor leadership, he would weigh up the credentials of Mr Rudd against Mr Abbott, but expressed concerns Mr Rudd’s leadership style may not work in the dynamics of a hung parliament.

Mr Oakeshott expressed similar views about reconsidering his support for Labor.

QLD Independent Bob Katter said he was not interested in the machinations of other parties as he was focusing on promoting his new party in Queensland.

Another wild-card in the leadership tussle is Tasmanian Independent Andrew Wilkie who has declared he would prefer to work with Mr Rudd over Ms Gillard after the PM reneged on the poker machine reforms deal she made with him, after the 2010 election, when Mr Slipper became speaker.