Former Labor treasurer Wayne Swan has unloaded on Tony Abbott for missing a 2009 parliamentary vote on global financial crisis stimulus measures after passing out drunk.
Mr Swan, who has publicly accused Mr Abbott of lying about the reason for his absence for years, said questioned why he had now finally admitted it.
"Perhaps he's just utterly and completely lost the plot, it's hard to know," he said in Brisbane on Friday.
Mr Abbott will say in an upcoming episode of the ABC television series The House that he passed out drunk in his office and was unable to be woken.
He missed crucial votes in the House of Representatives relating to the Labor government's global financial crisis spending bills.
Mr Swan said it showed Mr Abbott was focused on himself and not the Australian people.
"When the jobs of Australians were on the line, Tony Abbott didn't care," he said.
"His recklessness knows no bounds."
Mr Swan said the fact he was drunk showed how "self-indulgent" he was on that night.
"It says a lot about his negativity and it says a lot about his obsession with himself but it says a lot more about the modern Liberal party of Australia," he said.
"They didn't give a stuff about the jobs of Australians."
Mr Swan, now a backbencher, also took a swipe at Prime Minister Malcolm Turnbull, who was then opposition leader.
"He should've told the Australian public about this a long time ago," he said.
