Stephen Conroy "cannot stand" his boss Julia Gillard, while Bill Shorten harbours prime ministerial ambitions but is willing to wait for his "moment in the sun".
At least that was the impression picked up by the US embassy in a series of meetings during the first year of the Rudd government.
A confidential cable sent by then US ambassador Robert McCallum to authorities in Washington in 2008 identifies the Victorian factional allies as potential thwarters of the rising political fortunes of the Prime Minister - then deputy prime minister.
The cable, published yesterday by WikiLeaks, also identifies "socially conservative" veteran union heavyweights - Shop Distributive and Allied Employees Association national secretary Joe De Bruyn and Australian Workers Union national president Bill Ludwig - as being potential obstacles to Ms Gillard assuming the Labor leadership.
A spokesman for Senator Conroy last night flatly rejected the suggestion contained in the diplomatic cable that he loathed the Prime Minister two years before he aided her ascension to the top job.
"Any claim or suggestion that Senator Conroy does not fully support Julia Gillard in either a personal or professional sense is outrageous, ill-informed and wrong," the spokesman said. "Prime Minister Gillard is the best person to lead the Labor Party and the government to the next election and beyond."
Senator Conroy, along with Wayne Swan and Defence Minister Stephen Smith, were famously dubbed "roosters" by former Labor leader Mark Latham for their plotting during Simon Crean's fraught leadership.
In a separate diplomatic cable yesterday, US consul-general in Melbourne Michael Thurston wrote that Mr Shorten made "no bones" about his ambitions in politics.
"Shorten struck us as highly ambitious but willing to wait - at least for a while - for his moment in the sun," the cable said.
But bitter party rivalries are not the sole domain of Labor.
Mr Shorten said last night: "The nice comments are all true, and the
less flattering observations I don't agree with."
The latest cables also reveal deep animosity in Coalition ranks over the leadership of Malcolm Turnbull.
Former Howard government minister Mal Brough told Mr McCallum in Canberra in June 2008 that some members of the Liberal caucus were supporting Mr Turnbull's push for party leadership "only because they wanted to put him in a position to fail".
"Turnbull was only interested in Turnbull and his constant undermining of [Brendan] Nelson had hurt him in the eyes of many of his colleagues," the cable said.
A November 2009 cable - "Opposition melts down over climate change" - says Liberal Party deputy federal director James McGrath, who is identified as a protected source of information for the US, notes that key supporters of Mr Turnbull were pressing him to step aside for Joe Hockey.
Mr McGrath told US authorities that Tony Abbott and Right faction Liberal heavyweight Nick Minchin had told Mr Hockey he would be elected unopposed to the Liberal leadership if he agreed to concessions on the deal Mr Turnbull had struck with the Rudd government on the emissions trading scheme.
A cable providing Washington with a "report card" on the Rudd government for 2009 said government sources had indicated that party elder John Faulkner had refused to be defence minister unless Greg Combet was appointed his junior minister.
Additional reporting: AAP