Federal Labor's climate change spokesman Mark Butler says he would accept any call by his leader to shift portfolios, if it helped end a rift within the caucus over the party's policy direction.
Mr Butler has come under fire from former shadow minister Joel Fitzgibbon, who quit Labor's frontbench this week amid a long-running dispute over the Opposition's carbon emissions and energy platforms.
Mr Fitzgibbon called on Anthony Albanese to dump his South Australian counterpart from the portfolio, arguing Labor had lost three consecutive elections with Mark Butler calling the shots on climate change strategy.
Backbench senator Alex Gallacher echoed that criticism on Thursday.
When asked if he would step aside to break any deadlock in the party, Mr Butler replied "absolutely, in a heartbeat".
"I take the view that as a frontbencher, you have a standing letter of resignation in the drawer of your leader," he told ABC Radio Adelaide.
"My view is the leader at any time can pick up the phone and say it's time for you to shift or go."
Mr Butler would not comment on whether he had discussed his future as shadow climate change minister with Mr Albanese this week.
He said any shift would be based on merit, not on the agitations of noisy backbenchers, "completely rejecting" assertions Labor had lost at the ballot box because of his work.
"I would accept it with 100 per cent confidence that he was making that decision on its merits, not because Joel Fitzgibbon or because Senator Gallacher … had called on him to do it," Mr Butler said.
"It would not impact the way in which he assessed our policy options, and the way in which he assessed our long-standing commitment to taking strong action on climate change in a way that drives jobs and drives investment."
Labor is united in its calls for Australia to reach net zero carbon emissions by 2050. However, the point of contention within caucus is whether the party's medium-term targets will be too ambitious, and cost it votes in some parts of the country.
Mr Fitzgibbon's decision to quit the shadow ministry, and spend much of the last parliamentary sitting week publicly criticising his former frontbench colleagues' direction in a string of media interviews, has raised concerns about Mr Albanese's leadership coming under threat.
Mr Butler denied his tenure as shadow climate change minister was tied to Mr Albanese's leadership prospects.
