Barnaby Joyce is disappointed concerns raised about him in a National party vetting process have been leaked, but is confident he'll win preselection.
Every Nationals candidate for the federal election due in 2019 is being put under the microscope after the Section 44 crisis, which resulted in more than a dozen MPs forced to resign from parliament.
Some party members are reportedly refusing to support Mr Joyce's preselection bid over fears he has more skeletons in his closet.
Mr Joyce said he was "very disappointed" the details of the closed-door vetting meeting had leaked, but said it came from anonymous sources with vested interests.
"They try to get at you on innuendo rather than fact," he told AAP on Wednesday.
The former deputy prime minister and Nationals leader stood down in February after it was revealed he had split with his wife and was having a baby with an ex-staffer.
But Nationals federal president Larry Anthony expects Mr Joyce to successfully pass vetting for his NSW seat of New England.
"In the New England electorate I am the only candidate who stuck up their hand for preselection," Mr Joyce said.
The process was introduced after a number of MPs across several parties were found to be ineligible because they held dual citizenship - including Mr Joyce.
"He's got to get through that like everyone else," Mr Anthony told AAP.
"I have every confidence that he'll get through that process."
Nationals leader Michael McCormack said Mr Joyce had the support of his party colleagues.
"He's going through the normal vetting processes as is the case with all National party candidates, whether they're a candidate, whether they're a sitting member, indeed whether they're the deputy prime minister as I am," he told reporters in Queensland.
"I went through the same vetting process and you have to fill out a long and involved form, and you have to make certain undertakings."
Mr Anthony says the preselection for New England will be held on November 17, and a couple of hundred local Nationals members will vote.
Labor shadow treasurer Chris Bowen said he wasn't surprised Nationals preselectors were having second thoughts.
"Barnaby Joyce is the most overrated politician in modern Australia," he told reporters.
Mr Joyce won a by-election in 2017 forced by the discovery of his dual citizenship.
Prime Minister Scott Morrison appointed Mr Joyce as special envoy for drought assistance when he took over from Malcolm Turnbull.