07/02/2017 7:29 AM AEDT | Updated 07/02/2017 9:55 AM AEDT

Bernardi Resigns From Liberal Party, Leaving Turnbull In Turmoil

Bernardi is set to make a formal announcement on Tuesday.

Fairfax: Alex Ellinghausen
Bernardi will reportedly announce he is leaving the Liberal Party on Tuesday.

Liberal Senator Cory Bernardi has phoned Prime Minister Malcolm Turnbull to resign from the Liberal Party, to instead serve on the crossbench as he sets up his own "Australian Conservatives" party.

Over the past day, Bernardi's colleagues had made public and private pleas with the conservative politician to stick with the Liberal Party, instead of defecting.

He telephoned Turnbull around 7am, ahead of a prayer service to mark the start of parliament on Tuesday. The South Australian senator is expected to make a formal statement to the Senate at 12.30pm on Tuesday.

Senator Bernardi's name was on every politician's lips as they arrived for the start of parliament for 2017.

Under grey Canberra skies, Coalition anger grew as speculation turned to the confirmation of the resignation phone call between Bernardi and Turnbull.

Reporters pressed politicians at the traditional church service and on the doors of the Senate and the House of Representatives.

Bernardi was nowhere to be seen, but Deputy Prime Minister Barnaby Joyce urged his departing colleague to "pray, pray hard."

While the Leader of the Government in the House, and long-time Bernardi adversary, Christopher Pyne took to Twitter to urge him to immediately resign his seat, as the only "honourable course," and contest again as an independent.

Finance Minister Mathias Cormann told the ABC the South Australian senator's move was "disappointing" while Immigration Minister Peter Dutton labelled it a "betrayal".

Dutton said there was "no chance of others following" believing people "will be angry about any defection, angry about the betrayal of Liberal party values".

"We can most effectively defeat the Labor party at the next election if we're united and we stick together as a party," Dutton told ABC Radio.

Conservative Coalition members Eric Abetz and George Christensen have confirmed they will not follow Bernardi's lead, however Christensen warned the government "cannot abandon conservative causes, conservative principles and conservative policies."

Independent Senator David Leyonhjelm said he is looking forward to Bernardi becoming his new senate wingman while Nick Xenophon used the moment to warn the conservative senator Australia is not U.S. President Donald Trump's doormat.

Bernardi has previously said Trump's election inspired him to be a "catalyst for change" on home soil, after watching the U.S. election from New York, on his secondment at the United Nations.

Earlier, Liberal MPs had been making their last calls to Bernardi after rumours circulated about his decision on Monday morning.

On Monday night, Liberal MP Craig Kelly said Bernardi should have "one last think" before making any announcement, as speculation soared around the senator leaving to join the crossbench as an independent senator pushing more conservative policies.

"You can do a lot more inside the Liberal party, working for, arguing those things that you believe in, than actually outside the tent," Kelly told the ABC.

Coalition ministers Scott Morrison and Kelly O'Dwyer publicly warned the South Australian senator against stepping away from Liberal Party, which he was elected to represent in the July election.

"People would feel that their trust has been violated if somebody stood for a particular political party and then left that political party so shortly after an election campaign," O'Dwyer told the ABC on Monday morning.

A report from Fairfax claims Bernardi's decision to leave the Liberal Party was cemented after a conversation with former prime minister Tony Abbott.

After watching the revolt against establishment politics in the U.S. and Britain, Bernardi reportedly confided in Abbott.

The pair ran through a number of options, including Bernardi defecting from the Liberal Party. Days later those details appeared in The Australian newspaper, Fairfax reported. Abbott said he never leaked their conversation to the newspaper.