A spokesperson for Liberal frontbencher Malcolm Turnbull has denied he is canvassing backbenchers for support in a potential vote on the leadership.
As some Coalition MPs publicly call for a change, Mr Turnbull, who led the party in opposition before Tony Abbott, has been touted as a potential replacement.
Reports have emerged that two MPs have revealed Mr Turnbull has called them to directly gauge their support.
ABC News has been unable to confirm that.
Mr Turnbull's office said he was not trying to secure numbers if there was a spill.
However, the spokesperson told the ABC Mr Turnbull had taken calls and made calls to concerned colleagues.
Mr Turnbull's supporters suspect the report is an attempt by Mr Abbott's backers to "flush out" the former leader and force him into publicly ruling out a challenge.
Yesterday, Foreign Minister Julie Bishop - who is also regarded as a possible leader - told Cabinet that she would not challenge Mr Abbott and was not "campaigning" for the job.
Mr Abbott had earlier yesterday sidestepped questions about whether she had refused to give him such a commitment in a meeting on Sunday.
In an interview today, Ms Bishop did not rule out standing for the leadership if the spill was instigated by other party room members.
"I should not be called upon to rule out what I'm clearly not doing," she told the AFR.
"Seriously, it leaves open the possibility that I might be hit by a bus tomorrow. I'm not dealing in hypotheticals, I will deal with reality.
"I said to the PM yesterday that I am not campaigning for his job, I am not ringing the backbench seeking support, I am not counting numbers. I support the leader, PM Tony Abbott.
"Tony Abbott is the leader, Tony Abbott is the PM, so I am supporting him."
She also declined to criticise government MPs who have publicly questioned Mr Abbott's performance.