Barnaby Joyce to contest Nationals leadership for "invisible Australians"

Earlier on Monday, Mr Joyce said he would contest the leadership if a spill was called but he would not instigate the challenge.

However, the former deputy prime minister appears to have had a change of heart, phoning Mr McComack to inform him of the challenge.

"With due respect, there will be a spill, and I will be standing," Mr Joyce said.

"The prime minister talks about the quiet Australians, our job is to represent the near invisible Australians.

"We've got to make sure that we are not a shadow of another party, that we speak with our own voice."

READ ALSO

Resource and Energy Minister Matt Canavan, who is family friend of Mr Joyce, has offered his resignation from the front bench to support Mr Joyce in the spill.

Mr Canavan said he was backing Mr Joyce because he was an "effective fighter" for regional Australia.

"We need a bulldog, we need a fighter to fight back against those who want to take away people's coal jobs, who want to shut down cane farms," Mr Canavan said.

"I do think a change in direction here will allow us to do that better."

It's been two years since Mr Joyce stood down as Deputy Prime Minister and Nationals leader following intense scrutiny of his affair and a sexual assault allegation.

Mr Joyce won't reveal if he believes he'll have the votes, but there are plenty within the party room disgruntled with Mr McComack, calling for him push the Nationals' agenda more vocally in the media.

A host of people are expected to put their hand up for the party's deputy leader position, which is vacant following Senator Bridget McKenzie's resignation in the wake of the sports rort scandal.