Kevin Rudd sees Malcolm Turnbull as a "brick wall" to his international ambitions.
But the prime minister might not have been the extent of the blocks, with Attorney-General George Brandis saying he never saw any submission from the Department of Foreign Affairs recommending the government support Mr Rudd's bid to run for the United Nations' top job.
"I have seen no document or submission prepared by DFAT to that effect," Senator Brandis told ABC radio on Tuesday.
"But ... ultimately these decisions are a matter for cabinet; cabinet is not at all bound to accept advice that it receives from public servants."
Mr Turnbull told the former prime minister on Friday morning he had decided, after consulting his cabinet, Australia would not support Mr Rudd's candidacy for the position of UN secretary general.
Mr Rudd needed that endorsement to be able to formally enter the race.
The next day he spoke to a Young Labor meeting in Brisbane, video of which was posted on failed Labor candidate Pat O'Neill's Facebook page, describing Mr Turnbull as one of the "brick walls" in life.
"I've got a very dark deep secret for you, sometimes it'll turn to shit and sometimes it won't turn out perfectly," Mr Rudd said.
"I've had a modest experience of that, just a little bit, including (Friday)".
Opposition Leader Bill Shorten said Mr Turnbull had explaining to do over the whole affair.
"It's clear to me that Mr Turnbull's put his own political survival ahead of prior positions he may have had," he told ABC radio.
The Australian Financial Review reported on Tuesday a slim majority of cabinet supported Mr Rudd's bid, but Mr Turnbull and deputy prime minister Barnaby Joyce decided at the end of the meeting to quash it.
Senator Brandis said he supported the prime minister.
"An orthodox cabinet process means every member of cabinet supports every decision of cabinet and I adhere to that process," he said.
