Shadow home secretary Andy Burnham is considering standing to be the mayor of Greater Manchester.
The former Labour leadership contender has yet to decide whether to seek the role when it comes up for election in 2017, his spokesman said.
Mr Burnham, who was comprehensively defeated by Jeremy Corbyn when he ran for the Labour leadership in 2015, intends to remain a member of the shadow cabinet even if he does seek the role.
A spokesman for Mr Burnham said: "Approaches have been made to Andy Burnham to give consideration to this role.
"It is early days and no decision has been taken. Whatever the decision, he will continue to serve the leader of the party and stay in the shadow cabinet."
The new post of Greater Manchester mayor was created with the devolution of extra powers to the region as part of George Osborne's "Northern Powerhouse" agenda.
Former Cabinet minister Mr Burnham has been MP for Leigh in Greater Manchester since 2001 and the role would give him the chance for one of the biggest jobs in local government in England.
Former Labour MP Tony Lloyd is serving as the interim mayor of the combined authority until the first election for the role in 2017.
Shadow chancellor John McDonnell said he hoped Mr Burnham would continue his career at Westminster to enter government in 2020, but acknowledged the lure of the Greater Manchester role.
He told Sky News: "I can see why people in the North are approaching him because he is such a good advocate for the North and he has been a tremendous MP in Parliament.
"If he goes, it would be a real loss to Parliament and a loss to the Labour Party as we go into government in 2020, but I can see why people are approaching him."
He added: "I would want him to stay on and be the home secretary when we go into power because I think he is such a tremendous asset for the Labour Party, but I know how dedicated he is not just to his constituency, but how he has been a dedicated advocate for the North as well.
"He is a northern lad, he has got real grassroots and I can see how he is tempted by that and why others are saying 'why not think about it'."
Liverpudlian Mr Burnham has won plaudits for the way he has championed the cause of the victims of the Hillsborough disaster.