Cory Bernardi has dismissed demands from furious former colleagues that he quit Parliament and give his Senate seat back to the Liberal Party, saying it is "the political class defending their self interest".
The South Australian senator says his new breakaway conservative movement will strengthen the Coalition government.
The dissident senator quit the Liberal Party on Tuesday to sit as an independent in the Senate, claiming the political class had lost touch with the Australian people and become beholden to "expedient, self-serving, short-term ends".
His new Australian Conservatives party will target only the Senate and serve as an "anchor" for disaffected Liberal voters, he said, suggesting he would preference the Liberal Party.
Before announcing his decision, Senator Bernardi told Prime Minister Malcolm Turnbull that the 2015 leadership change was a catalyst for his defection and he warned Mr Turnbull that forces were now ranging against him.
Senior MPs scoffed at this. All acknowledged the opinion polls were concerning but it was too early in the term to be contemplating a leadership push and there was no obvious candidate anyway.
Old guard conservatives including Tony Abbott and Eric Abetz implied that Mr Turnbull had facilitated the Bernardi defection by not being conservative enough.
"While Cory and I have sometimes disagreed, I'm disappointed that more effort has not been made to keep our party united," Mr Abbott said.
But the majority of the party, including conservatives, circled wagons around the Prime Minister and blasted Senator Bernardi for ratting just seven months after being re-elected for another six years in the Senate on the Liberal Party ticket.
'Breaking the promise'
"If one seeks to restore confidence in the political class, it is a poor way to begin by breaking the promise one makes to one's electors to serve for the political party on whose platform and whose ticket one stood," said Liberal Senate leader George Brandis.
"What Senator Bernardi has done today is not a conservative thing to do because breaking faith with the electorate, breaking faith with the people who voted for you, breaking faith with the people who have supported you through thick and thin.
"In the seven months since the federal election, nothing has changed. There is no policy for which the Liberal Party and the government stands today, which is not the same as the platform on which Senator Bernardi sought election by the people of SA only seven months ago."
Mr Turnbull told Senator Bernardi he should quit the Senate when the pair spoke by phone earlier on Tuesday.
"I asked him how he could justify remaining in the Senate having been elected as a Liberal only seven months ago. He could not answer that question," the Prime Minister said.
Immigration Minister Peter Dutton, one of the most senior conservatives in the government, lashed out, saying Senator Bernardi's actions would only split the conservative vote and facilitate the election of a Labor government.
"I think people will be angry about any defection, angry about the betrayal of the Liberal Party values," he said. Treasurer Scott Morrison concurred.
At the last election, Senator Bernardi received only 2043 first preference votes, or 0.025 per cent of a quota. The SA Liberal Party received 345,767 votes and he was elected on its ticket.
But Senator Bernardi rejected the criticisms from his former colleagues as "the political class defending their self interest". Voters in SA knew who he was when he was re-elected, he said, and that he had not changed.
No voting concerns
Despite the anger, senior Liberals were unconcerned in so far as they believed Senator Bernardi would still vote with the government. His defection means the government now needs nine crossbench Senate votes to carry legislation when it is opposed by Labor and the Greens.
Senior sources said Senator Bernardi, a loner for some years, had grown disenchanted when Mr Abbott was prime minister and squibbed on such conservative issues as diluting section 18C of the Racial Discrimination Act. The leadership challenge had further disillusioned him and he said on Tuesday people hankered for the stability of the Howard government days.
Sources close to him said his hatred of fellow South Australian Liberal and moderate Christopher Pyne, who has significant influence in the Turnbull government, was a key factor as well.
Senator Bernardi is a social conservative, who espouses small government and lower taxes, rejects the science of climate change, vehemently opposes same-sex marriage, and was warning about Muslim immigration many years before it became a mainstream issue.
He said he had become tired of struggling internally against policies with which he did not agree but suggested he would support the current policy agenda of lower company taxes and budget repair.
He said his new party would prioritise stronger families, free enterprise, limits to the size and scope and reach of government while seeking to rebuild confidence in civil society.
Trade Minister Steven Ciobo said Senator Bernardi had spent his whole career causing internal trouble and "had never laid a glove on the Labor Party".
Despite his defection causing damage to the government, Senator Bernardi has no appetite to see another prime minster rolled.
But he believes the Liberal cause has become more hopeless since the election result, for which no one has been held accountable.
Billionaire Gina Rinehart, who is very close to the South Australian, said she had not funded Senator Bernardi's new party.