Malcolm Turnbull has dismissed Labor questions about whether the decisions of ministers who have been referred to the High Court are now in legal doubt.
Deputy Prime Minister Barnaby Joyce, cabinet colleague Fiona Nash and stood-aside minister Matt Canavan are all facing tests of their eligibility in the High Court over dual citizenship.
Constitutional experts have suggested if the ministers are disqualified from parliament their decisions could be challenged in the courts.
Labor frontbencher Tony Burke asked the prime minister in parliament on Tuesday whether he had been advised of any legal risk to the ministers' actions under section 64 of the constitution.
That section says: "After the first general election no minister of state shall hold office for a longer period than three months unless he is or becomes a senator or a member of the House of Representatives."
Mr Turnbull told parliament he was aware of section 64.
"It's been there for quite a long time and I can assure the honourable member that the government is very satisfied that the ministers he's referred to are fully entitled to serve as ministers just as they are entitled to serve in this parliament," Mr Turnbull said.
Shadow attorney-general Mark Dreyfus earlier told reporters it was misleading for the government to argue Mr Joyce and Senator Nash could serve as ministers if they are ruled to be ineligible.
"That is not correct. The three months started from the date of their eligibility which is the date of their election to the parliament - and it ran out in October," Mr Dreyfus said.
Mr Turnbull declined to say, in answer to another Labor question in parliament, how many executive orders, grants, delegations, appointments and legislative instruments had been made by Mr Joyce since doubts arose over his citizenship.
"The government does not doubt the deputy prime minister's eligibility to sit in the parliament," the prime minister said.
Asked why the ministers had been referred to the court if the government had no doubt about their status, Mr Turnbull said: "In order to give the High Court the opportunity to clarify the law on this matter."
Labor sought to bring on a motion to have Mr Joyce, who will be acting prime minister when Mr Turnbull heads to Samoa later this week, stood aside until the court decision was finalised.
The government used its numbers to defeat it.
