Mr Shorten was prompted to speak to the broadcaster after Mitchell publicly called on the Labor leader to clarify the record, following the ABC's final episode of The Killing Season, which examines the Rudd-Gillard years, on Tuesday. Radio presenter Neil Mitchell. "I think he has got questions to answer," Mitchell said. "He has been caught out deliberately misleading you and me about his involvement in the 2013 leadership battle." Government MP Arthur Sinodinos seized on the incident, describing it as a defining moment for Mr Shorten.

"It could be his carbon tax moment," Senator Sinodinos told Sky News on Wednesday. Illustration: Matt Golding "I think this does go to his fundamental character." The Killing Season described a meeting between Mr Rudd and Mr Shorten on the night of the press gallery's Midwinter Ball on June 19, 2013. It quotes Mr Rudd's former adviser, Patrick Gorman, who said that Mr Shorten met Mr Rudd in Richard Marles' office. Two days later, on Mitchell's program, Mr Shorten was adamant that he had not been asked to "review" his support for Ms GIllard. When specifically asked, Mr Shorten said on June 21 that he had not spoken to Mr Rudd about the leadership.

During his program on Wednesday morning, Mitchell replayed the relevant audio from both The Killing Season and his own program, and said Mr Shorten had "questions to answer". He didn't want to make an already diabolical situation worse During the 11am news, Mr Shorten called in and spoke to Mitchell off air. "It would be fair to say, he apologised to me for what happened," Mitchell told his listeners. He also read out a statement from Mr Shorten's office that said he was "caught on the hop" and he regrets the answer he gave.

"He didn't want to make an already diabolical situation worse," the statement read. Earlier on Wednesday, Mr Shorten did not buy into Mitchell's concerns. "Well, we've seen The Killing Season and the debate about all of the history there and that's what it is. It is history. It is not my job as Leader of the Opposition to be the curator of the museum of Labor," he told reporters in Canberra. The Labor leader is preparing to front the trade union royal commission next month, amid reports he oversaw a controversial deal which saw a Melbourne builder pay the union dues of its own employees through large fees to the union. Mitchell told Fairfax Media that while MPs regularly rang up during his program to "try and spin something" it was "very unusual" for them to call to clarify the record as Mr Shorten had done.

The broadcaster - who has known Mr Shorten for many years - said he would have preferred the Labor leader to talk on air, but Mr Shorten declined. Mitchell said it had been frustrating during the Rudd-Gillard years because journalists knew that politicians were not always telling the truth. Loading "There was nothing we could do about it." Follow us on Twitter