LIBERAL MPs and senators have filed into their Parliament House partyroom for an emotionally draining leadership ballot, which Malcolm Turnbull’s head counters believe will make him prime minister.

There are normally 101 Liberal MPs that sit in the partyroom, but two — Dean Smith and Michael Ronaldson — are likely to miss tonight’s meeting.

That means there will be 99 votes in the ballot and the winning side will need 50 to claim victory.

“Anything with a five in front or better will do,” a source said of the vote.

Tony Abbott called the ballot quickly rather than wait for tomorrow morning as expected. But he then delayed it for a few hours amid speculation he was waiting for two supporters to get back to Canberra.

He also had to shore up a ticket to contest the deputy’s job vacated by Foreign Minister Julie Bishop.

DEFIANT ABBOTT VOWS TO FIGHT FOR LEADERSHIP

Earlier, a defiant Tony Abbott has made it clear that he will not go quietly.

Showing the feisty style with which once made him a decent fighter in the boxing ring, Tony Abbott invoked rank-and-file support as he aggressively slammed Malcolm Turnbull’s leadership challenge which is likely to happen tonight.

The Prime Minister said Liberal grassroots troops were angered by the threat to his job and were equally annoyed by the possibility of replicating Labor’s act of replacing prime ministers (twice) in its last period in office from 2007 to 2013.

“I’ve been heartened by the messages of support flooding in to Liberal MPs’ offices this evening saying most emphatically: ‘We are not the Labor Party’,” Mr Abbott told reporters.

“This country needs strong and stable government and that means avoiding at all costs Labor’s revolving door prime ministership.

“The prime ministership of this country is not a prize or a plaything to be demanded. It should be something earned by a vote of the Australian people.”

Earlier today when announcing the leadership spill, Malcolm Turnbull was critical of Mr Abbott for using too many slogans. Mr Abbott repeated several of those slogans in his speech, saying: “You can trust me to deliver a stronger economy and a safer community.”

Meanwhile Sky News reports that influential Social Services Minister Scott Morrison will support Tony Abbott, while Foreign Minister Julie Bishop will stand as Mr Turnbull’s deputy.

Sky has also been told that Mr Turnbull has the support of more than half of the Liberal partyroom.

Mr Abbott can count on the support of Treasurer Joe Hockey, who has pledged his “absolute loyalty” to the Prime Minister.

Mr Hockey, the co-target with Mr Abbott of Mr Turnbull’s earlier criticism of economic policy, also took up the theme of Labor-like leader removal.

“The position of prime minister is a gift of the Australian people. You have the right to hire, and only you have the right to fire,” he said.

“We cannot, we must not become a carbon copy of the Labor Party.”

The Treasurer also defended his own record.

“Mr Turnbull made a number of claims about economic leadership that are completely unfounded,” Mr Hockey told reporters.

He denied the government was heading in the wrong direction and didn’t spare the plotters: “The disloyalty of some has been outrageous. We have an economic plan that is being delivered and is working.”

Mr Abbott is also expected to receive support from cabinet ministers Peter Dutton, Mathias Cormann, Kevin Andrews, Josh Frydenberg and Eric Abetz, as well as government whip Andrew Nikolic.

Senior sources told News Corp Australia that Mr Turnbull’s camp was confident they had the numbers to win the challenge against Mr Abbott.

“The numbers have grown significantly since February,” one MP said.

“Particularly from people on the right. There are big shifts in the ministry from the right.”

TURNBULL SAVAGES ABBOTT’S LEADERSHIP

Malcolm Turnbull has savaged Tony Abbott’s leadership style, announcing that he will challenge him for the prime ministership.

In a stinging press conference in Canberra this afternoon, Mr Turnbull said Mr Abbott was not “capable” of the “economic leadership” needed to run the country.

He said the Liberal Party had lost the past 30 Newspolls in a row.

“A little while ago, I met with the Prime Minister and advised him that I would be challenging him for the leadership of the Liberal Party,” he said.

Mr Turnbull said he regretted making the decision before the Canning by-election on Saturday, adding there were few occasions that were ideal for “tough calls”.

The alternative was to wait and allow the government’s problems to “roll on and on and on” without clear air.

Mr Turnbull said it was clear the government had not been successful in providing the economic leadership that the nation needed.

“It is not the fault of individual ministers,” he said.

“Ultimately, the Prime Minister has not been capable of providing the economic leadership … he has not been capable of providing the economic confidence that business needs.”

Mr Turnbull said there must be an end to policy on the run and captain’s calls.

The government needed to be truly consultative with colleagues, MPs and the wider public.

“We need an open government that recognises that there is an enormous sum of wisdom both within our colleagues in this building and, of course, further afield.”

Nationals Deputy Leader Barnaby Joyce has warned Liberal MPs the Coalition agreement would need to be renegotiated if Mr Turnbull wins a challenge against Mr Abbott.

There is no love lost between the junior Coalition partner and Mr Turnbull, going back to his time as opposition leader.

“The one thing they need to realise is they will have to renegotiate the Coalition agreement,” Mr Joyce told AAP.

Mr Turnbull didn’t make clear when a vote would occur, but there are reports it will be held tomorrow morning.

Mr Turnbull has resigned as Communications Minister.

Mr Turnbull says he will maintain Liberal policy to hold a plebiscite on same-sex marriage and he has vowed to stick with the party’s existing targets on climate change cuts.

Mr Turnbull met with Prime Minister Tony Abbott and Foreign Minister Julie Bishop this afternoon to explain his intentions.

It is understood that Ms Bishop first requested the spill. There is now speculation she could resign from cabinet, according to ABC Radio.

WHAT THEY STAND FOR

Tonight’s contest will pit a man who has been described as one of the most socially conservative Australian prime ministers in decades against a challenger some think is not conservative enough.

Unlike Mr Abbott, Mr Turnbull supports gay marriage, wants Australia to replace the British monarch with an Australian president as head of state, and backs a policy of making polluters pay for their carbon gas emissions.

Mr Turnbull, a 60-year-old former lawyer and merchant banker known for his moderate views, has long been considered Mr Abbott’s chief rival.

Mr Turnbull was opposition leader for two years before he lost a partyroom ballot by a single vote to Abbott in 2009. His downfall was his belief that Australia should make polluters pay for their greenhouse gas emissions.

Opinion polls show that Mr Turnbull is more popular than Mr Abbott, but many of those who prefer him vote for the centre-left Labor Party.

Mr Turnbull is the type of classical liberal that has become rare in the oddly named party, which has been overrun by conservatives in recent decades. It was called the Liberal Party when it was established in the early 1940s because it believed in individual freedoms, while their Labor opponents favoured state control and heavy regulation.

Mr Abbott and Mr Turnbull are both Rhode scholars.

Mr Abbott, a 57-year-old former Roman Catholic seminarian, has long suffered an image problem, particularly among women. He is regarded as gaffe-prone and old-fashioned in his views on women’s place in society.

Mr Turnbull is a self-made multi-millionaire regarded by some as arrogant and has been nicknamed “The Silvertail” due to his wealth and privilege.

‘WE NEED A DIFFERENT STYLE OF LEADERSHIP’

After keeping quiet about his leadership ambitions for the best part of a year, Mr Turnbull in a press conference this afternoon finally explained his reasons for taking on the PM.

“This is not a decision that anyone could take lightly,” he began.

“I have consulted with many, many colleagues, many Australians, many of our supporters, in every walk of life. And this course of action has been urged on me by many people over a long period of time. It is clear enough that the government is not successful in providing the economic leadership that we need. It is not the fault of individual ministers. Ultimately, the Prime Minister has not been capable in providing the economic leadership our nation needs. He has not been capable of providing the economic confidence that business needs … We need a style of leadership that … explains the challenges and how to seize the opportunities. A style of leadership that respects the people’s intelligence, that explains these complex issues and sets out the course of action we believe we should take and makes a case for it. We need advocacy, not slogans.”

Mr Turnbull said the public had “made up their minds about Mr Abbott’s leadership”.

“There must be an end of policy on the run and captain’s calls,” he said.

“John Howard’s government most of us served in and yet few would say that the cabinet government of Mr Abbott bears any similarity to the style of Mr Howard. So that’s what we need to go back to.

“We have to make a change for our country’s sake, for the government’s sake, for the party’s sake.”

— with wires