Supporters of Mr Dutton believe the required 43 votes need to topple Mr Turnbull can be found, however the prime minister appears to still believe he has the numbers. The next election is due by 2019.
A report in The Australian suggests Mr Turnbull had lost confidence of nine Liberal cabinet ministers - half of the Liberal contingent.
Mr Spence denies he's been calling for federal Queensland MPs to dump Prime Minister Malcolm Turnbull.
Labor Prime Minister Kevin Rudd was ousted by his deputy Julia Gillard in 2010.
Turnbull declared the leadership vacant within minutes of the Liberal MPs gathering in Parliament House for their regular meeting on Tuesday morning, triggering a vote.
Dutton immediately resigned from the home affairs super ministry, moving to the backbench where he will not be constrained by cabinet solidarity which has seen him lock in reluctantly behind Turnbull's position on the national energy guarantee and tax cuts for big business.
Three years later, Australia's first woman prime minister was gone when Rudd finally took his revenge after a failed 2012 coup attempt.
'I think this stability in our government has helped key outcomes like the strong performance we had on jobs'.
Mr Turnbull's risky move may have backfired as it exposes the weakness of his position and the size of the split between the two factions of the Liberal Party.
This week Mr Turnbull was hit by former prime minister Tony Abbott for his backflip on plans to legislate the Paris emissions reduction target.
"That is what people are telling me and that is what the government wants to do", he said.
One Nation leader Pauline Hanson said she would not support legislation that allowed government's to reduce emissions targets through regulation, opening up another battle for the government in the Senate if it fails to secure Labor's support.
Malcolm Turnbull called the spill after what was clearly massive pressure from the Dutton camp.
"We are not going to propose legislation purely for the goal of it being defeated", he said.