Coalition MPs have dished the dirt on each other in an explosive new documentary about knifing Malcolm Turnbull, exposing details of the "heated" fight which became a tipping point in the leadership spill.

A senior minister who backed Peter Dutton also claims the Home Affairs Minister "drove" the coup against Turnbull and was gathering supporters for "quite some time" in the first episode of Sky News' Bad Blood/New Blood miniseries.

The documentary, which airs on Tuesday, reopens barely healed wounds in the Coalition just a week before parliament resumes, when Prime Minister Scott Morrison aims to start fresh with his newly formed government.

It reveals details of a "tense" exchange between Craig Laundy and his good friend Queensland MP Luke Howarth at Canberra's Wild Duck restaurant on the Monday night of "spill week" in August 2018, which became a pivotal moment as Liberal MPs grappled with the decision to dump their leader.

Leadership rumblings had escalated earlier that day when Turnbull caved to conservatives and dropped a key part of his signature National Energy Guarantee.

"When I got there Craig said something like 'You're not supporting this madness, are you' and then we just had a frank discussion," Howarth tells the documentary's host David Speers.

"It was pretty straightforward and honest. What I was going to suggest to Malcolm is that actually he resign so we didn't need a ballot and we didn't need any division."

Laundy, who retired as an MP this year, unleashes on "backstabbing" in politics in his interview, saying he prefers frank conversations.

"He and I had a very tense exchange, a heated exchange where he was saying 'Malcolm's gotta go' and I was saying 'Malcolm's gotta stay," he said.

Laundy called Turnbull immediately after the dinner to warn him there could be a move against him at the party room meeting on Tuesday.

Turnbull called a snap leadership spill the next morning.

He narrowly defeated Dutton, 48 votes to 35, but it was the beginning of the end.

"You have Craig Laundy and Luke Howarth who catch up for these dinners sitting there and just going toe-to-toe over a glass of wine and a meal about whether they should dump the prime minister or not. This is how these big moments in Australian politics come about," Speers told News Corp this week.

"It does give you a real insight into the division within the party, the way individuals were grappling with what to do and debating with their friends and colleagues whether they should actually oust the prime minister or not."

Dutton's supporters are divided over his role in the spill but former Trade and Defence Industry Minister Steve Ciobo, a fellow Queenslander, bluntly claims: "Peter drove this."

He said their first "serious" conversation about the leadership was when they flew to Canberra for the Sunday night cabinet meeting before 'spill week'.

"Obviously you need to have someone who is willing to, in many respects, take the bullets, and Peter was of the view that it was better that he put himself forward than to continue to wait for something to change," Ciobo says.

He also claims Dutton told him he had been "speaking to people for quite some time".

Howarth, however, claims Dutton told him the move against Turnbull was driven by other MPs and he "didn't ask for it".

The two-part series, which investigates how the party went from a spill to a "miracle" election victory in nine months, is the first in a couple of new documentary outings for Sky News Australia. It will be followed in July by the Peter Stefanovic-helmed two-parter on Melbourne gangland scandal, Lawyer X: The Untold Story.

Bad Blood/New Blood premieres 25 and 26 June at 8pm AEST on Sky News and will be available to stream On Demand on Foxtel following its broadcast.