When asked about his treatment by Mr Murdoch's newspapers on Tuesday, Mr Rudd shrugged it off.

"In terms of his views, and his determination to see Mr Abbott elected as prime minister, and his determination to see the end of myself, it's a free country," he said.

But Mr Rudd upped the ante on Wednesday evening, calling for Mr Abbott to come clean on any discussions he had conducted with Mr Murdoch about broadband.

"I've only just been looking back on the files today and discovered that in fact Mr Abbott's NBN policy was launched at the Fox studios here in Sydney. I would like to hear some answers to what discussions Mr Abbott may have had with Mr Murdoch on the future of Australia's National Broadband Network," Mr Rudd said.

On Sunday, Fairfax newspapers ran a comment piece by Paul Sheehan alleging Mr Murdoch's News Corp was attacking the government because it saw Labor's National Broadband Network as a commercial threat to its subscription television network Foxtel.