Barnaby Joyce’s plan to retain his seat of New England is in doubt as the former deputy prime minister is forced to pass a tough new Nationals vetting process.

Nationals leaders maintain that every party candidate is being put under the microscope after the Section 44 citizenship crisis, which saw more than a dozen MPs forced to resign from parliament.

But several party members are refusing to support their former leader’s candidacy after a year of crisis including sexual harassment allegations, the breakdown of his marriage over an extramarital affair and a referral to the high court over dual citizenship.

The dissenting members fear Mr Joyce has “more skeletons in his closet”, after being forced to abandon the leadership in the face of revelations of an extramarital affair and claims of sexual harassment, Sky News reported on Wednesday.

Nationals federal president Larry Anthony said Mr Joyce was going through the same internal vetting process as every candidate in the country.

The new 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.”

Mr Joyce told AAP 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 said on Wednesday.

“In the New England electorate I am the only candidate who stuck up their hand for preselection,” Mr Joyce said.

Its believed some party members are arguing Mr Joyce did not declare his extramarital affair with former staffer Vikki Campion when he filled in his paperwork ahead of the last federal election in 2016.

But 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 said 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 said the preselection for New England will be held on November 17, and a couple of hundred local Nationals members will get to vote on who should be their candidate.

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.

He resigned as leader of the party in February after his affair with Ms Campion and her pregnancy was revealed and went to the backbench until he was appointed a special envoy for drought assistance by Prime Minister Scott Morrison.

Mr Joyce is yet to comment.

– with AAP