The architect of Labor's controversial tax policies, Chris Bowen, will run for the Labor leadership.
Labor's treasury spokesman Chris Bowen has confirmed he will run for the Labor leadership, setting up a contest with fellow frontbencher Anthony Albanese.
Announcing his plan to run, Mr Bowen stood by controversial tax changes that some have blamed for Labor's loss.
"A controversial policy, for which, no doubt, we lost some votes. But I don't accept that it is why we lost," Mr Bowen told reporters on Tuesday.
"We also lost the election because of the policies we don't have, like a death tax. They were more people raising the death tax on the polling booths with me than ... franking credits."
He conceded he should have chosen his words better when he said "if you don't like it, don't vote Labor" earlier in the year.
Speaking to reporters outside his childhood home in Sydney's west, Mr Bowen said he would be a different style of leader to the outgoing Bill Shorten and his rival Anthony Albanese.
"I'm my own man," Mr Bowen said.
Mr Albanese, from the party's left faction, confirmed on Sunday he would nominate to be the next Labor leader, while Jim Chalmers is also being encouraged to run by members of the right faction.
A 'positive campaign'
After Mr Bowen's announcement, Mr Albanese told reporters the pair had been "friends for a very long time" before continuing to make his case for the leadership role.
"I'm determined, as I'm sure Chris is as well, to ensure that this will be a positive campaign," he said.
"I myself will be campaigning very much on my record and also a clear view that people have of me. What you see is what you get.
"If you look at my history, I believe firmly in nation building infrastructure as a key driver of economic growth. I'm very passionate about it."
Mr Albanese refused to criticise the campaign run by Bill Shorten.
"I have said before and I will say it again so you can have it on rotation if you like, there will be no criticism of Bill Shorten from me."
Other potential rivals are yet to declare their hand.
Labor MP Jim Chalmers, who hails from the right, said on Monday night he was considering a tilt at the position.
"I'm considering it. I'm talking to my colleagues about it. I don't think it's unreasonable that a few of us take some time to work out what we want to do," he told ABC's Q&A program.
Deputy Labor leader Tanya Plibersek confirmed on Monday that she won't be throwing her hat into the ring for the top job, despite having the backing of Bill Shorten and Julia Gillard.
"Now is not my time," she said in a statement on Monday.
"At this point, I cannot reconcile the important responsibilities I have to my family with the additional responsibilities of the Labor leadership."
Ms Plibersek intends to continue as Labor deputy leader, until the party's leadership is determined.
Labor national president Wayne Swan paid tribute to Ms Plibersek, but declined to say who should run.