Labour’s sole Scottish MP has indicated he will only return to Jeremy Corbyn’s frontbench team if shadow cabinet elections are reinstated.
Former shadow Scottish secretary Ian Murray said the step could serve as an olive branch to MPs who have criticised the Labour leader.
His intervention came as the party prepared for its conference in Liverpool this weekend.
On Saturday, the winner of the contest between Mr Corbyn and challenger Owen Smith will be announced.
The veteran left-winner is expected to win the race easily and will need to try to unite his party after a divisive campaign.
Other senior Labour figures were keen to have their say in advance of the conference, with former foreign secretary David Miliband declaring the party had not been further from power since the 1930s.
He branded Labour “unelectable” and criticised Mr Corbyn’s “half-hearted” campaigning for Britain to remain in the European Union as “a betrayal of millions of working people”.
Former shadow chancellor Ed Balls, who lost his seat at last year’s general election, also had a go.
He said he was unable to remember a time when the views of the Labour party membership were so “disconnected” from voters in marginal seats.
Meanwhile, the Islington MP has insisted his leadership style is unlikely to change should he beat Mr Smith.
But he has said the “slate will be wiped clean” after the result, adding: “If I am re-elected leader, I will reach out to and work with all Labour MPs to form a broad and effective opposition to this divisive and floundering Tory government.”
Earlier this week, Labour’s ruling National Executive Committee put off a decision on MPs’ demand to be allowed to elect members of Mr Corbyn’s shadow cabinet.
Mr Murray insisted he “certainly would” return to his former post if shadow cabinet elections were restored, but added that not returning to the election system “makes it much more difficult”.
The Edinburgh MP said it was one Mr Corbyn used to support, describing him as “one of the biggest opponents of removing shadow cabinet elections”.
He added: “I think if this is a way of uniting the party it’s a good start, it’s an olive branch, and I would suggest Jeremy grabs it with both hands.”
Mr Murray also dismissed the idea that Labour would split if Mr Corbyn is re-elected.
