UPDATED: The Liberal party will vote for the next prime minister at a party-room ballot at 9.15pm.

Party members have arrived at Canberra to cast their votes, with Malcolm Turnbull needing at least 52 votes to secure the leadership over Tony Abbott.

Mr Turnbull may have secured as many as 60 of the 102 votes of the parliamentary Liberal party, according to the Sydney Morning Herald.

Mr Abbott was flanked by about 25 colleagues as he walked towards the party room to find out his future, but deputy leader Julie Bishop was not amongst the group.

Watch the announcement live by clicking the video above.

In what has been one of the most tumultuous nights in Australian political history Prime Minister Abbott responded to Malcolm Turnbull's leadership challenge by calling an immediate party-room ballot.

Just hours after Mr Turnbull publically challenged Mr Abbott for the leadership of the nation, Mr Abbott fired back, saying he was up for the fight at tonight's ballot.

"I will be a candidate and I expect to win," Mr Abbott said earlier this evening.

"You can trust me to deliver a stronger economy and a safer community."

Mr Abbott also warned the party as a whole that it was time to stand together.

"This country needs a strong and stable government and that means avoiding at all costs Labor's revolving door prime ministership," he said.

"I firmly believe that our party is better than this, that our government is better than this.

"The destabilisation just has to stop."

Mr Turnbull made his play for the top job after speaking with the Prime Minister after today's question time, resigning as Communications Minister.

He then made his leadership bid public at a press conference at the senate courtyard in Canberra.

"It is clear enough that the government is not successful in providing the economic leadership that we need," Mr Turnbull said.

"Ultimately the prime minister has not been capable of providing the economic leadership our nation needs.

“This course of action has been urged on me by many people over a long period of time.”

In a ninemsn poll, 61 percent of readers believed Mr Turnbull had done the right thing by calling for a ballot.

Commenting on his decision to run, Mr Turnbull said there was a need to restore a "traditional cabinet government".

"There must be an end to policy on the run," he said.

"We need a style of leadership that explains the complex challenges.

"We need a style of leadership that respects people's intelligence.

"We need advocacy, not slogans."

In his own address to the media, Treasurer Joe Hockey offered his support to Mr Abbott and said any negative comments about the economy made by Mr Turnbull were unfounded.

"He has never said to me or the cabinet that we are heading in the wrong economic direction," Mr Hockey said.

"The disloyalty of some has been outrageous."

Defence Minister Kevin Andrews was also quick to side with Mr Abbott in a speech directed as much at his Liberal party colleagues as it was towards the Australian public.

"The question for myself and my colleagues tonight is who is best placed to lead us to victory at the next election," Mr Andrews said.

"We have a clear choice."

Jeff Kennett, former premier of Victoria also came out strongly against Mr Turnbull's move saying he would not vote Liberal again if the former communications minister succeeded in his challenge.

"Malcolm Turnbull, You self centered, selfish individual. It has always been about you," Mr Kennett said on Twitter.

Nine Network political editor Laurie Oakes said Mr Turnbull’s move suggested he had strong support in the party room.

“I understand that Malcolm Turnbull is getting support from some very unexpected quarters,” Mr Oakes said.

“Well if that’s the case, then he should have the numbers.”

Foreign Minister Julie Bishop met with Mr Abbott before question time today amid reports she will be Mr Turnbull’s running mate.

The move comes ahead of Saturday's crucial Canning by-election in Western Australia.