Christchurch city councillor Glenn Livingstone could stand for mayor if Lianne Dalziel decides not to seek a second term, he says.
Ms Dalziel said the past three years had taken an emotional toll and she was undecided about whether to stand again.
Despite elections being less than six months away, nobody had yet put their name forward as a mayoral candidate.
Mr Livingstone said both he and the mayor had their roots in the Labour Party and there would therefore be no point in standing against her.
But he said he would be interested in standing if Ms Dalziel did not put her name forward again and a right-leaning candidate did.
Mr Livingstone represents the earthquake-hit eastern suburbs and has been a councillor for the past six years.
He is a member of the Labour-aligned The People's Choice faction of councillors.
Meanwhile, Prime Minister John Key has praised Ms Dalziel and said he would gladly work with her again if she decided to stand for re-election.
On a visit to Christchurch today, Mr Key said despite what some commentators have said, Ms Dalziel had a good relationship with the government, which still had control of large parts of the city's rebuild.
"I think Lianne has put her heart and soul into the job. In the end, it's for her to decide whether she wants to continue as mayor, and if not, then I'm sure others will put their name forward and ultimately it is critically important that Christchurch gets a strong leader. But I've enjoyed working alongside Lianne. If she wants to coninue as mayor, the government will have a very constructive working relationship with her."