Liberal MP backs citizenship audit

A Liberal MP is backing a Greens call for a citizenship audit of all federal politicians, insisting the government needs to clear the air.

The Turnbull government has rejected calls for an audit even though seven MPs and senators have been referred to the High Court, and backbencher Craig Kelly wants his colleagues to reconsider.

"It's in our best interest to clear this issue up as quickly as we possibly can," he told ABC radio on Tuesday, warning confusion in the media is reflected in the government's bad polling.

But unlike Australian Conservatives senator Cory Bernardi, Mr Kelly concedes the audit should wait until after the High Court decides the fate of those with a cloud over their eligibility.

Cabinet minister Christian Porter has defended the process already in place.

"Anyone in parliament who has concerns or is not perfectly sure about their status has got this very strong opportunity now to join what will be a High Court hearing in the very near future," he told ABC radio.

The High Court will hold a directions hearing on Thursday in the cases of the Nationals Barnaby Joyce and Matt Canavan, One Nation senator Malcolm Roberts and Greens senators Scott Ludlam and Larissa Waters.