There was a near unanimous view within the party yesterday that Malcolm Turnbull was in deep trouble but no one knew what to do about it because there was no standout alternative candidate.

Senior Liberals, including the Senate leader, Nick Minchin, yesterday urged their party to get behind Mr Turnbull, whose leadership has been damaged by the OzCar affair.

Others, who did not want to be named, said Mr Turnbull was still the best option as leader but, with Parliament resuming next week, the next fortnight would be critical. "We'll wait and see what will happen," a frontbencher said.

The Senate will vote next week on the emissions trading scheme, which has split the Coalition and will test Mr Turnbull.

The frontbencher Andrew Robb dismissed suggestions that he should take the job to help minimise a feared election loss.

The two leading candidates for the leadership in the event of a change are Joe Hockey and Tony Abbott, but neither is keen on the job before the election.

Mr Turnbull said last night on the ABC's Q&A: "I have the full support of my colleagues. This is a rough-and-tumble game."

The Family First senator, Steve Fielding, said yesterday he would support the Government in establishing a Senate privileges inquiry into the Coalition's collusion with the Treasury official Godwin Grech in the OzCar affair.

Senator Fielding, who used his vote to block Labor's push for a Senate inquiry when the Government first tried six weeks ago, said he was concerned at information released this week that showed Mr Grech had scripted the Senate inquiry process with the Opposition.

Mr Turnbull has slumped in recent opinion polls as a result of the OzCar affair backfiring when a damning email produced by Mr Grech turned out to be a fake.