New England MP Barnaby Joyce will challenge Michael McCormack for the leadership of the National Party if the position is spilled.
Nationals MPs will meet in Canberra on Tuesday to vote for a new deputy leader after Bridget McKenzie resigned over the sports rorts scandal.
"If there is a spill then I will put my hand up," Mr Joyce told the Seven Network on Monday.
"I will leave that up to my colleagues. They can make the call."
With Senator McKenzie stepping down as deputy there will be a ballot for her position, but it is up to the Nationals' partyroom as to whether there is a leadership spill.
Mr Joyce, who resigned as deputy prime minister in February 2018, talked up his record as Nationals leader.
"We had the maximum number of cabinet ministers we ever had, we won back more seats than we had in about 30 years, we delivered some big changes," Mr Joyce said.
Labor's agriculture spokesman Joel Fitzgibbon relished in the leadership rumblings.
"What you just heard was a vote of no confidence in the current leadership of the National Party," Mr Fitzgibbon said.
"Barnaby Joyce just told us that the National Party is dysfunctional and indeed hopeless. My concern is that a dysfunctional government just got a whole lot more dysfunctional."
Australian Associated Press