Former Labor frontbencher Craig Emerson has called on Kevin Rudd to quit parliament, warning he will "recklessly destabilise Labor leaders" if he stays on.
Mr Rudd was re-elected in his Brisbane seat of Griffith on Saturday, but announced he would stand down as Labor leader after the party's election defeat.
He hasn't spoken publicly since conceding defeat to Tony Abbott on Saturday night and may not resurface until he greets the prime minister-elect at the Lodge in Canberra later this week.
As Labor searches for a new leader, there's speculation Mr Rudd could stay on as a backbencher for the three-year term.
That's an unthinkable prospect for Dr Emerson, a supporter of Julia Gillard who quit the Labor ministry when Mr Rudd deposed her as prime minister in June.
"Kevin Rudd's continuing presence in the parliamentary Labor Party will see him do what he has always done, and that is willingly, wilfully, recklessly, destabilise Labor leaders," he tells ABC TV's 7.30 program on Monday.
"It is in the best interests of the party for Kevin Rudd to leave the Parliament."
Dr Emerson also suggested the outgoing prime minister was responsible for leaks that damaged Labor's election chances in 2010, adding that one so "destructive" and "hell bent on revenge" should not be rewarded.
Other senior Labor figures, including former ministers Stephen Smith and Greg Combet, have also said Mr Rudd should quit for the sake of the party as it rebuilds following its defeat.
But others have credited Mr Rudd with saving Labor from an election wipeout, and believe he has more to offer in the new parliament.
Former treasurer Chris Bowen - a key Rudd ally - said the former prime minister could make an ongoing contribution to Labor and Australia, although it was up to him to decide what that might be.
"He should be given all the time he needs to make that decision and those announcements and it's entirely a matter for him," Mr Bowen said on Monday.
Labor's new federal figurehead in Western Australia Alannah MacTiernan said Mr Rudd had saved the party from annihilation and left them in with a fighting chance.
"I don't think we should be trying to force Kevin out of the parliament," said Ms MacTiernan.
But Dr Emerson wasn't convinced, arguing Mr Rudd had returned as prime minister and the election was a "disaster for Labor".