Mr Arbib is credited with saying Mr Rudd could not be allowed to remain on the frontbench after the changeover because he was untrustworthy, and that Mr Shorten, who was at that stage a key organiser of the pro-Gillard push, could not be given industrial relations in the cabinet because of its pivotal role and extensive ties into the labour movement. Then Prime Minister Julia Gillard and Bill Shorten during question time in August 2012. Credit:Andrew Meares "He [Senator Arbib] pulled out a ministerial list and started going through his thoughts about Julia's next ministry ... he then went through and had a rant about Kevin Rudd and how he couldn't be allowed in the ministry," Mr Kitchener told the ABC's documentary series, The Killing Season. "And then he came down to Bill Shorten's name and he said that um you couldn't trust Bill Shorten, that he would do Julia in, that the one thing she couldn't do was ever give him industrial relations cause he'd use it to solidify the union base to knock her off." The advice was uncannily similar to views about Mr Shorten at the highest levels of Mr Rudd's new administration in 2007.

In an earlier episode, Mr Rudd's initial chief of staff David Epstein revealed he always thought Mr Rudd had erred by parking the ambitious Mr Shorten in the ranks of parliamentary secretaries responsible for disabilities. Former Prime Minister Julia Gillard, during filming of The Killing Season. "Why alienate someone who you think is a potential threat? It's better to keep them closer in my view," he said. Mr Rudd however had argued in response that marginalising Mr Shorten had never been his intention because he believed the former Australian Workers Union boss and rookie MP was an up-and-comer. "I actually regarded Bill then, as one of the hopes of the side," Mr Rudd told the program.

It is a matter of record that Mr Shorten came to believe strongly in Ms Gillard's leadership credentials and played a pivotal role in the organising of her move in June 2010 to take over from Mr Rudd. The record also shows that as Ms Gillard's industrial relations minister, Mr Shorten eventually lost faith in her too and switched back to Mr Rudd – a key moment in the collapse of Ms Gillard's support in June 2013 – leading to Mr Rudd's second stint in the top position. Also of note in the documentary is the period of Mr Rudd's leadership immediately following the underwhelming outcome of the December 2009 Copenhagen climate talks. Mr Rudd had attended the summit with high hopes of a binding international deal to establish integrated carbon abatement, having left his ministry with the view that a double-dissolution election in early 2010 would be called to expose the new Abbott opposition as out of step on carbon trading. But instead he returned forlorn and dispirited, amid claims he had described the Chinese as "ratf---ers".

Asked if he said that, he responded: "I cannot recall because I'd frankly not been to sleep for a couple of days". "Does it sound like you?" he was asked. "Ah well, I'm a person given often to fairly direct speech and it's pretty disappointing when you have the concerted opposition of a couple of other countries who are so significant in the world." In other comments, a former Labor senator Mark Bishop said the coup against Mr Rudd in 2010 could have been avoided with a simple statement from then treasurer Wayne Swan that it was "nonsense", but that had not come.