The man who many tip to replace Barnaby Joyce says there is no challenge to his leadership – “at the moment”.

Veterans Affairs Minister Michael McCormack had what some media outlets referred to as a “trainwreck” interview on Sky News in which he repeatedly dodged questions about the leadership and refused several  times to support Mr Joyce as leader.

“There is no challenge at the moment … he has the party’s support,” Mr McCormack said on Monday.

Throughout the lengthy exchange, Mr McCormack was asked at least seven times whether Mr Joyce had his personal support to stay on as leader.

Mr McCormack repeatedly gave the same response, saying “Barnaby Joyce has the support of the National Party”.

When told it looked like he was refusing to support his leader, Mr McCormack eventually said: “Of course I support Barnaby Joyce, he’s our leader, he’s been a very good leader.”

“If I knew what was going to happen this week, I’d be down at the local race track betting on the horses I knew were gonna come home,” he said.

“Of course there’s been talk about what may or may not happen but at the moment Barnaby Joyce is the leader of the National Party. At the moment, he has the support of the National Party.”

Minister for Veterans' Affairs @M_McCormackMP: This has been unfortunate, but there is no spill, there is no vacancy, @Barnaby_Joyce will continue to be the leader as long as he gets the support of @The_Nationals party.

MORE: https://t.co/WOGIaWN1R0 #SkyLiveNow pic.twitter.com/BNHxlLB44q

— Sky News Australia (@SkyNewsAust) February 19, 2018

Mr McCormack also said he had not been approached by colleagues to challenge Mr Joyce at the next Nationals’ party room meeting when Parliament resumes next Monday.

Asked if he would run for the leadership if Mr Joyce quit as leader, Mr McCormack said: “It’s a very hypothetical question and we’ll have to see what happens in the future.”

Mr McCormack, the Member for Riverina and a government minister since July 2016, is considered the main contender to replace Mr Joyce.

Earlier, Prime Minister Malcolm Turnbull conceded the Deputy Prime Minister’s affair with his ex-staffer and now pregnant partner, Vikki Campion, had harmed the government.

Mr Joyce claims his party supports him, but Mr Turnbull told 3AW he did not know if that was the case.

Nationals backbencher George Christensen said he had 100 per cent support for his leader, and his electorate backed Mr Joyce too.

“The response has been that he’s done nothing wrong, it’s a personal issue and people should just get off his back,” Mr Christensen told reporters.

The latest Newspoll showed the Coalition had lost the small gain it made on Labor earlier in the month.

“It’s distracting and it’s unhelpful,” Mr Turnbull said.

The Prime Minister would not say whether he confronted Mr Joyce about the affair when rumours first began circling and whether Mr Joyce denied the relationship.

“I’m not going to go into the private discussions I’ve had with him other than to say that at no stage did he say to me that he was having a sexual relation with this lady,” he said.

Mr Turnbull said his wife Lucy had been in touch with Mr Joyce’s estranged wife Natalie since the affair, which he last week labelled “a shocking error of judgment”.

Mr Joyce called those comments “inept”, but insisted he and Mr Turnbull continued to have a strong working relationship.

“Like most people in a strong business relationship, there are times you need to discuss your views because that’s how you resolve things,” Mr Joyce told Fairfax Media.

Two in three voters believe Mr Joyce should quit as Nationals leader, a Newspoll published in The Australian found.

Meanwhile, Opposition Leader Bill Shorten confirmed for the first time on Monday that Labor would not overturn the Prime Minister’s recently announced ministerial sex ban.

–with AAP