Attorney General George Brandis has thrown his support behind the government's top lawyer after Friday's decision by the High Court was contrary to his advice.
The High Court ruled five parliamentarians who hold dual citizenship constitutionally ineligible to nominate for parliament at the 2016 election, including deputy prime minister Barnaby Joyce and deputy Nationals leader Fiona Nash.
"I have an enormous amount of confidence in Stephen Donaghue the Solicitor-General," Senator Brandis told Sky News on Sunday.
He points out that Mr Donaghue only weeks earlier had a victory in the High Court over the government's equal marriage postal survey.
Senator Brandis also has no reason to believe any other member of the coalition government is a dual citizen.
Mr Joyce, who now has to fight a by-election in his seat of New England, said he had taken the advice of the Solicitor-General because he had to base his decisions on something.
"That the High Court had a different view. I accept that and now we're into the campaign," Mr Joyce told the Nine Network.
Manager of Opposition Business Tony Burke said Labor is combing through decisions that were taken by Mr Joyce as a minister saying there is a "whole lot of legal doubt" over them.
"I think there's a reason why they never revealed the Solicitor-General's advice. I don't believe for a minute it was as strong as they were claiming," Mr Burke told ABC television.
Independent MP Cathy McGowan and NXT MP Rebekha Sharkie have indicated they will back the government in a no-confidence motion.
But Mr Burke said both had voted with Labor when it was trying to get Mr Joyce to stand aside pending the court decision and every member voted for a banking royal commission and all but one supported keeping Sunday penalty rates.
"Now, each of those decisions, the government was able to have its way by one vote. And we now know that vote wasn't even lawful," Mr Burke said.
Senator Brandis said the government was looking carefully at this.
"But the observation I would make to you, I doubt there are many if any decisions that would be relevant in any event," he said.
"I do not think we will see a problem here but of course the Labor party will try to play games because they do not have an interest in steady government of the country."
