Australian Prime Minister Malcolm Turnbull looks set to stand aside as his government prepares for its second leadership contest in a week.

His opponents claim they have the support to call for a party room meeting on Friday, at which a motion challenging his leadership is expected.

Turnbull has said he is prepared to step down if the motion is carried. However, he has also questioned the eligibility of his main challenger, Peter Dutton, to sit in parliament.

Turnbull allies Treasurer Scott Morrison and Foreign Minister Julia Bishop are both reportedly prepared to stand for the top job in the event of leadership challenge, or spill motion.  

The prime minister's announcement came at a hastily arranged news conference in Canberra on Thursday, in an attempt to counter party members demanding the contest.

He said he was waiting for advice from Solicitor General Stephen Donaghue regarding Dutton's eligibility.

Dutton's case relates to a company belonging to his family trust allegedly receiving state funds, and whether this falls foul of Section 44 of the country's constitution.

"We expect that advice to be available first thing in the morning," Turnbull said. "That may impact on [Dutton's] decision to run or not."

A majority of lawmakers need to sign a letter demanding Turnbull convene a party room meeting, at which he has pledged to invite a spill motion.

Turnbull's skill as a political tactician is in full swing, observers say, as he hems his party members into a dilemma of their own making.

Turnbull's conditions imply that a spill would prompt his departure from parliament, necessitating a by-election for his vacant seat and endangering the coalition's one-seat majority.

At the same time, he is amplifying doubts over his party cohorts' chosen alternative, Dutton.

"These are momentous times," Turnbull said, "and it's important that people are accountable for what they're doing."

“We’re seeing the cautious legal mind of Malcolm Turnbull at work,” said Norman Aborjensen, a fellow at the Australian National University’s School of Public Policy. “I think he’s playing by the rules when he’s not been given a lot of room to maneuver. But all his political skills, for what they are, count for almost nothing in this environment.

"The numbers are against him and the dynamics of the party.”

Aborjensen added that there is a “slim possibility” of Turnbull surviving. But it is more likely, he said, that Turnbull's successor will be forced to call an early election, possibly in September or October.

Calls for a leadership change have been growing throughout the week, as Dutton's supporters seized on policy rifts and Turnbull's unpopularity in the polls. Turnbull won a slim victory over Dutton in a leadership challenge on Tuesday.

The Australian dollar fell by about 0.9% against the U.S. dollar on Thursday amid the political turmoil. The country's benchmark stock index was down 0.4% as of 1 p.m. local time. The currency and stocks pared some losses after Turnbull's news conference.

"Australians have become used to federal political instability over the past decade," said Andrew Ticehurst, rates strategist at Nomura Australia. But "this has not prevented a further extension of Australia’s 27 consecutive years of growth." – Asian Review