Labor is seeking to ramp up pressure on Barnaby Joyce as the deputy prime minister appears to have warded off a push by a small number of Nationals to oust him.
The Nationals leader's relationship with his pregnant partner Vikki Campion raised concerns about the potential misuse of taxpayer funds, after she was shuffled around jobs in other senior MPs' offices.
A rent-free townhouse provided to him by a businessman friend also became the subject of Labor questions in parliament on Wednesday.
And Labor has demanded to see the details of taxpayer-funded flights Mr Joyce and Ms Campion took in 2017 - setting a deadline of 5pm Thursday for the release of documents.
Malcolm Turnbull and senior Nationals on Wednesday expressed confidence in Mr Joyce, despite a handful of Nationals MPs agitating for him to consider his future.
The prime minister reaffirmed his deputy would act for him while he visited the White House next week.
While Nationals deputy Bridget Mackenzie was also giving Mr Joyce her whole-hearted backing.
"I'll give you my solid, rolled-gold guarantee here that come tomorrow, come Friday, Barnaby Joyce will be leading the National party," Senator McKenzie told Sky News on Wednesday.
Nationals whip Michelle Landry said the party room sorted out their issues in a get-together on Tuesday night.
"Obviously some of the guys were upset with what has happened but they're prepared to give him another chance," she told ABC radio.
Mr Joyce has denied breaching the ministerial code of conduct, which says frontbenchers cannot employ close relatives or partners or get them work in other ministerial offices "without the prime minister's express approval".
He argues Ms Campion was not his partner when she worked in his and Matt Canavan's office.
Damian Drum was not a minister when she transferred to his office.
Labor also attacked Mr Joyce, who once said city-dwellers should move to Armidale because houses were cheaper there, for living rent-free for six months in an Armidale townhouse belonging to his friend, multi-millionaire businessman Greg Maguire.
Mr Joyce declared the townhouse rent on his members' interests register even though he said he did not need to do so.
Labor senator Kimberley Kitching on Wednesday tabled a notice of motion calling for the details of Mr Joyce and Ms Campion's "special purpose travel" and any international flights.
Senator Canavan was also grilled over whether he or his office recommended Ms Campion for departmental jobs.
Ms Campion is due to give birth in mid-April.
Mr Joyce late last year separated from his wife Natalie after 24 years of marriage.
Australian Associated Press