Chris Bowen has offered to serve as shadow treasurer in opposition, amid calls for Labor to avoid selecting a "messiah" as its next parliamentary leader.
The outgoing treasurer said yesterday he would not be a leadership contender after concluding that he was not the best candidate.
Mr Bowen did not declare who he believed should be Labor leader but there are only two candidates being considered - Anthony Albanese and Bill Shorten.
It is understood that Mr Shorten will not contest the leadership if Mr Albanese, the outgoing deputy prime minister, decides to run.
Internally, there is no appetite for more conflict and Mr Albanese is widely regarded inside Labor as having the superior parliamentary skills to take on Prime Minister-elect Tony Abbott.
But Mr Albanese is unde- cided, despite being encouraged by colleagues, including Kevin Rudd.
Tony Burke is also considered leadership material but he believes his time is not now.
Mr Bowen said Labor must quickly move to provide a united and stable opposition.
"Each of us involved in the Labor Party needs to consider what role we can best play in that rebuilding process so that the Labor Party is the most viable prospect possible whenever the next election is held," he said.
Victorian Labor MP Kelvin Thomson said he would not be a candidate for the frontbench so that he could freely speak his mind on issues of concern to him, such as population growth, climate change, unchecked rainforest and other habitat destruction, poverty, war and terrorism.
In a chip at Mr Rudd's leadership style, Mr Thomson warned the party against allowing power to be centralised with the leader.
"This is fundamentally undemocratic," he said.
"Ordinary voters have plenty of opportunities to catch up with me and other members of Parliament and make their views known to us. They have no hope of accessing prime ministers and premiers.
"And the trend to leave everything to a messiah leads to poor decisions which have been made by a small group of people and not submitted to proper scrutiny."