Former Victorian Liberal premier Jeff Kennett has slammed Malcolm Turnbull for "gross disloyalty" and "extreme egotism" over his Liberal Party leadership challenge.

Mr Turnbull defeated Mr Abbott 54-44 in the secret ballot and will become Australia's 29th prime minister.

Mr Kennett said he was "profoundly disappointed" by Mr Turnbull's actions.

"This act by Malcolm Turnbull is one of gross disloyalty, extreme egotism and he is, without a doubt, the Kevin Rudd of the Liberal Party," he told ABC News 24.

Mr Kennett said Mr Turnbull was not a team player.

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"He might be smart, he might be wealthy but the one thing he never has been and never will be, he's never been a team man and teams win, individuals don't," Mr Kennett said.

Mr Kennett said the Australian public was tired of "personal self-interest overriding national interest".

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"The opportunity was there for the party to come together as a team, to march into Canning as a team," he said.

"We would have been absolutely undefeatable.

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"The public want leadership, the public are sick and tired of this personal self-interest overriding the national interest all the time."

Mr Kennett told ABC Radio Mr Turnbull had been "trying to build up his own popularity".

"He has been standing aside from his leader, going outside his portfolio, expressing his own views against that of the Cabinet... while in particular the Government was getting on as best they could with governing in difficult circumstances," he said.

Mr Kennett isolated the Government's boat turn-back policy as an example, calling it "perhaps the most humane policy Australia has introduced in years when you look at what's happening in Europe".

He said Mr Abbott's poor results in the polls should not be surprising, given Mr Turnbull has been "out there expressing a different view from this leader for two years".

"Can I remind you, I took on government here in Victoria in difficult circumstances," he said.

"My popularity got down to 19 per cent. We won the next election."