Abbott says "very confident" to remain as Australian PM

Tony Abbott has reiterated that he is "very confident" he will remain as Australia's prime minister, despite increasing pressure to call for a leadership spill in the near future.

Earlier in the week, three federal government MPs publicly revealed that Abbott no longer had their support and called for a vote to decide the leadership problems as soon as next week's party room meeting.

There have also been reports circulating that many more would support a change in leader, with communications minister and former party front man Malcolm Turnbull looming as a potential candidate to replace Abbott.

However, the prime minister remained defiant on Thursday, telling reporters in Melbourne that he is adamant he will still be the country's leader at the end of next week, when the party room meeting has concluded.

"I am very confident," Abbott said. "I know my colleagues, I trust my colleagues, I respect my colleagues."

Abbott's comments in Melbourne coincided with yet another senior Liberal figure, Arthur Sinodinos, failing to put his full support behind the embattled Australian leader.

The New South Wales senator and former chief of staff to John Howard had said his support for Abbott was "not unconditional".

However, members of the National party have pleaded with their Liberal colleagues to remain patient with Abbott and not to make any rash decisions in relation to their leadership issues.

Nationals senator John Williams said on Thursday: "Those who are panicking in the Liberal party, this is no time for panic."

"Tony Abbott was elected by the people to lead the country. Give him time, let him do his job and then judge us next election in my opinion."

Nationals members would be unable to vote if the Liberal party does call for a leadership spill.