Malcolm Turnbull has attacked his former colleagues for "insane conversations" around energy that are still alive seven years on from him being prime minister.
Australia's 29th prime minister sledged the coalition while unveiling his official portrait - which is customary for all past prime ministers - at Parliament House on Thursday.
The former Liberal served in the top job from 2015 to 2018, first entering parliament as the Member for Wentworth in 2004.
He lamented recent discussions around renewable energy as the coalition's bipartisan support for net-zero shattered this month, saying there's "still reality denial, physics denial is still alive".
"It's interesting now that we're still having the same insane conversations on the right of politics about energy," he said.
"Energy policy should be made by engineering and economics, not ideology and idiocy.
"That's kind of common sense isn't it?"
His remarks came as the coalition failed to negotiate a deal with Labor on landmark environmental reforms earlier that morning, which was instead struck with the Greens.
Mr Turnbull doubled down on his criticism after the unveiling, saying the joint party "could have played an active role, but they chose not to".
"They're running on culture war issues, reality denial - it's really sad," he told reporters.
Opposition Leader Sussan Ley shook hands with Mr Turnbull after the unveiling.
During the unveiling, Prime Minister Anthony Albanese almost moved Mr Turnbull to tears after sharing a vulnerable moment that had "nothing to do with politics".
"Malcolm and (his wife) Lucy to me showed their character when they reached out to me at a difficult time in my personal life and had me to dinner at their house," Mr Albanese told the crowd.
"No one knows about it ... it was just a sign of character and decency and humanity, and I will never forget it."
The artwork was painted by Jude Rae, who met with the former prime minister six times for the portrait, finding him to be "charming and engaging".
She used a bright yellow background to convey this, which differs from other darker-toned prime ministerial portraits.
"(He is) an extraordinarily articulate communicator more interested in recent argument than political spin," Rae said.
"The high key yellow background emphasises the dynamism of the gesture, as does the choice of a standing rather than seated pose."
