Hockey, Turnbull say trust still exists

It's all happy families in federal cabinet.

Malcolm trusts Joe, Joe trusts Malcolm and no one wants to talk much about the time they both tried to sit at the head of the table.

A new biography, Hockey - Not Your Average Joe, has caused ripples thanks to its revelations about the Liberal Party leadership contest in 2009.

Joe Hockey and Malcolm Turnbull contested the ballot, which they ultimately lost to Tony Abbott.

Mr Hockey's wife, Melissa Babbage, told biographer Madonna King the treasurer felt wronged over the incident and Mr Turnbull had lost his trust.

"That really annoyed Joe and he won't trust Malcolm again," she says in the book.

At the book's launch on Thursday, Mr Hockey said otherwise.

"I trust Malcolm Turnbull," he told reporters, noting his wife had made those comments "a while back".

And on Friday morning, Mr Turnbull was equally blunt.

"I trust Joe and he trusts me," the communications minister told the Nine Network, adding that Joe was "a terrific guy".

Mr Turnbull insisted he was not the sort of person to give private assurances of one thing and then say the opposite on national television.

But the events of 2009 were "really ancient history" and he was not surprised people had different recollections of what was said.