It comes as fellow leadership contender David Gillespie pulled out of the running on Sunday afternoon.

The Assistant Minister for Children and Families was tipped as Mr McCormack’s key rival, however, Mr Gillespie publicly announced he would retract his nomination.

It leaves Mr McCormack as the only Nationals MP to publicly put their name forward for consideration.

EARLIER

Mr McCormack, the Minister for Veterans Affairs, has been heavily tipped as the favourite to replace Mr Joyce in recent days, but it is reported that three other National MPs will self-nominate for leadership. 

One Nationals member who has gone public with his view on the leadership is Senator John Williams.

Asked by journalists whether Mr McCormack would make a good National Party leader, Senator Williams said: “I think he would”.

“There’s probably several others as well,” he said. 

“Michael’s always been a good mate of mine, works hard, well presented, and does his job well, but there’s probably several who could do the same job.”

Mr Joyce resigned on Friday, after almost three weeks of controversy which began with news that the Deputy Prime Minister was expecting a baby with a former staff member who had also been shuffled in and out of high-paying jobs in the offices of two of his colleagues.

CSU lecturer Dominic O’Sullivan said convention – but not the Constitution – dictated that the Deputy Prime Minister should come from the House of Representatives rather than the Senate.

Professor O’Sullivan said this was the reason Mr Joyce had given up his spot as a senator for Queensland and contested the seat of New England.

He said NSW MP David Gillespie is another possible contender, but his bid could be hampered by his current involvement a High Court case over the ownership of a post office agency, which Labor argues could be a breach of the Constitution and means was improperly elected.

Darren Chester, who was demoted in a recent reshuffle is another contender, Professor O’Sullivan said, along with Darren Littleproud, who may be hampered by having only been in Parliament for two years. 

Former Nationals leader and Deputy Prime Minister Tim Fischer made headlines during his periods as Acting Prime Minister for "running the country from his farm at Boree Creek”.

Mr Fischer would not be drawn into debate but said he believed the party would rebuild after losing Mr Joyce as leader.

“There will be a renewal,” Mr Fischer said.