Four months after losing the leadership spill he instigated, Peter Dutton has broken his silence in an extraordinary spray at Malcolm Turnbull.

Key points: Malcolm Turnbull's downfall was brought about by his lack of political nous, the Home Affairs Minister said

Malcolm Turnbull's downfall was brought about by his lack of political nous, the Home Affairs Minister said Mr Dutton said the former PM's actions have undermined the Morrison Government

Mr Dutton said the former PM's actions have undermined the Morrison Government He said Mr Turnbull's poor management lost the Liberal Party 15 seats in the 2016 election

Calling the deposed prime minister spiteful and indecisive, the Home Affairs Minister said Mr Turnbull had brought about his own downfall because he "doesn't have a political bone in his body".

"Malcolm had a plan to become prime minister but no plan to be prime minister," Mr Dutton told Brisbane's The Sunday Mail.

He also criticised the former leader for actions he saw as undermining the Morrison Government.

"I am the first to defend the legacy of the Turnbull government," Mr Dutton said.

"Malcolm was strong on economic management, borders and national security, but Malcolm will trash his own legacy if he believes his position is strengthened by seeing us lose under Scott [Morrison]."

He excoriated Mr Turnbull for not supporting the Liberal Party's candidate in the latter's former seat of Wentworth.

"Walking away from Wentworth and not working to have [Liberal Wentworth candidate] Dave Sharma elected was worse than any behaviour we saw even under [former Labor prime minister Kevin] Rudd," Mr Dutton said.

'The worst campaign in Liberal Party history'

Stating emphatically that he was not a stalking horse for former leader Tony Abbott or a right-wing "Bible basher", Mr Dutton said Mr Turnbull lost the Liberal Party 15 seats in the 2016 election.

"In 2016, Malcolm ran the worst campaign in Liberal Party history, and we ended up losing 15 seats and were left with a one-seat majority which just made the Parliament unmanageable. We were paralysed," he said.

Mr Dutton said it "became clear after we had lost 38 Newspolls in a row the government was going to be wiped out under Malcolm".

"I have no doubt Malcolm will rue the day he stormed in to the party room and declared the leadership open expecting to get a resounding vote," he said of August's events.

"His low vote destroyed him without any challenge necessary. It was then only a matter of when, and he used every trick to delay the vote, but it would have been untenable to leave Canberra that week without the leadership question being settled."

Mr Dutton said Mr Turnbull did not have former Liberal prime minister John Howard's touch, judgment or ability to deliver the message.

"We went from three-word slogans under Tony [Abbott] to 3,000 under Malcolm and our achievements weren't effectively communicated as a result," he said.

"Countless opportunities to strengthen the government or nail [Opposition Leader Bill] Shorten passed us by because Malcolm couldn't make a decision.

"Malcolm is charming and affable but he doesn't have a political bone in his body and it's not a criticism, but without political judgment you can't survive in politics and he didn't."

The Home Affairs Minister said the party had become "unrecognisable" under the former prime minister and Liberal supporters had "switched off".

He also took aim at the Turnbull Government's approach to energy policy.

"Energy policy had effectively become the 'greatest moral challenge of our time' and version after version just didn't work," Mr Dutton said.

AAP/ABC