Labour is calling for ACT leader Rodney Hide to be sacked as a minister after the resignation of David Garrett last week.
Mr Garrett quit the ACT Party abruptly, after revelations he used a dead child's identity to obtain a false passport in 1984.
Despite Mr Hide knowing that Mr Garrett had been discharged without conviction for identity fraud, he still encouraged him to stand for Parliament.
Labour leader Phil Goff says Mr Hide should be sacked as a minister.
But Prime Minister John Key says he has no reason to dismiss Mr Hide and nor does he want to.
But Mr Hide is standing his ground, telling Parliament on Tuesday he has never taken any action to conceal details of Mr Garrett's past.
He brushed off Mr Goff's call for him to be sacked as wishful thinking.
Earlier, Mr Hide said Mr Garrett had signalled to him that he intended to leave Parliament.
Mr Garrett is on two weeks' leave and is deciding whether to leave Parliament or stay on as an independent MP.
On his way into the party's weekly caucus meeting on Tuesday, Mr Hide said Mr Garrett has told him he wanted to do the right thing for ACT and for the Government.
However, Mr Hide said he had not put any pressure on Mr Garrett to make his decision before his leave is up.