Kevin Rudd has used a St Patrick's Day speech to joke about political backstabbing and challenges.
In a video of his address at a Queensland function posted on YouTube, Mr Rudd notes that as well as marking the Irish day of celebration the weekend represents the Ides of March, on which Roman Emperor Julius Caesar was stabbed to death by political conspirators in 44 BC.
Mr Rudd also refers to previous comments where he advised anyone wanting to engage in leadership speculation to cool down.
Kevin Rudd has a moment to ponder on the ALP backbench in parliament last week. Photo: Andrew Meares
"Today is also the Ides of March, a day which commands the stark attention of anyone involved in the fratricide - I mean the profession - of politics," he jokes.
"There has been a lot of speculation about politics of late and it's time to put a stop to it.
"It's time to turn off the cold shower ... to emerge from the ice bath ... and turn off the cryogenic storage tanks."
Mr Rudd then says he will make a "bold declaration".
"It's time to announce that I will challenge - any of the Liberal politicians to demonstrate that they have any more Irish blood than me."
He goes on to say that he has shared St Patrick's Day speeches with Opposition Leader Tony Abbott in the past.
"In 2010 when I was prime minister ... in 2011 when I was foreign minister and in 2012 when I experienced another career adjustment."
However, this year Mr Abbott had "fled the field", he said.
Mr Abbott later said the Brisbane St Patrick's Day dinner was generally a "rollicking" event and he wasn't surprised Mr Rudd had made some light-hearted comments.
"But obviously there's an edge to these remarks," he told reporters in Sydney on Sunday.
"It's an indictment of the ongoing tension in the Labor caucus and the ongoing division and dysfunction within the government."