Barnaby Joyce has reasserted the Nationals' critical role in the coalition government, as acting prime minister Julie Bishop admitted events of recent weeks had been damaging.
Mr Joyce would ordinarily be acting PM with Malcolm Turnbull travelling to Israel for leader-level talks and the centenary of the Battle of Beersheba.
Instead he's unemployed and fighting a by-election in his former NSW seat of New England after the High Court disqualified him from parliament due to his dual citizenship.
The messy week, which also included a member of Employment Minister Michaelia Cash's staff resigning after admitting leaking the raids on the Australian Workers Union, was reflected in Monday's Newspoll, which had Labor leading the coalition 54-46 per cent in two-party terms.
The coalition's primary vote has also dropped from 36 to 35 per cent, while Labor's remains steady at 37 per cent.
"Given the events of the last few weeks, it's not surprising that the Newspoll is as it is," Ms Bishop told reporters in Perth.
However, she noted Mr Turnbull had a 41-33 per cent lead over Bill Shorten as preferred prime minister and there was still 18 months to an election.
With some Liberal MPs fuming over the situation Mr Joyce and his deputy Fiona Nash - who was also disqualified - had put the government in, the Nationals leader said: "We are a coalition and without the National Party, there would be no government. That's a statement of fact."
Ms Bishop said the Liberals and Nationals were a "political family".
"There will be issues from time to time, but like any family you get over them and you move on."
The foreign minister said the government was now looking at whether "a few" decisions made by Mr Joyce and Senator Nash could be challenged in court following the High Court finding.
Labor has advice from two barristers that some decisions made after October 2016 are open to challenge under section 64 of the constitution which provides "no minister ... shall hold office for a longer period than three months unless he is or becomes a senator of a member of the House of Representatives".
Acting Labor Leader Tanya Plibersek said the government should have stood the ministers aside earlier.
"No doubt there will be some people who will be wondering whether they were treated fairly and whether decisions were made properly by Fiona Nash and Barnaby Joyce when they weren't properly elected to the parliament," Ms Plibersek said.
Mr Joyce, who faces the polls on December 2, said Labor's advice on ministerial decisions ran contrary to the constitution.
He said as an MP he was entitled to be a minister until either he died, he resigned or the High Court deemed him ineligible.
The Newspoll is the 22nd in a row with Labor in the lead, edging closer to the 30 Newspoll measure Mr Turnbull famously used to justify challenging Tony Abbott.
"I think we just continue to press on," said Liberal MP Craig Kelly, asked on Sky News what would happen when the 30 polls was reached.
