Cabinet minister Brendan O'Connor says it is entirely up to Kevin Rudd to decide whether he is an asset or liability for federal Labor.
Mr O'Connor, who backed Prime Minister Julia Gillard in last year's leadership challenge by Mr Rudd, said federal Labor MPs were firmly behind their leader.
"She's tough as nails," he told Network Ten on Sunday.
"That's why, regardless of what commentators may say, the caucus overwhelmingly supports her and wants to see these reforms done on behalf of all Australians."
Asked whether Mr Rudd was an asset, a liability or a human shield for the government, Mr O'Connor said, "It's entirely up to Kevin."
"I've got a high regard for Kevin Rudd.
"I think he certainly can play a very positive role."
To win the next election, due in September, Labor would have to have a "unity of purpose", he added.