Tamati Coffey has ruled out standing for the Labour Party in Phil Goff's Mt Roskill electorate if Mr Goff becomes the mayor of Auckland.
Mr Coffey, who stood in the Rotorua electorate at the last general election, said he moved out of Auckland for a better lifestyle in Rotorua and he did not want to return to Auckland, even if he was asked by the party to stand.
Mr Goff has said he would run for the Auckland mayoralty in next year's local government elections and would stand down from Parliament if he won.
Mr Coffey said he was committed to Rotorua and wished Mr Goff all the best in his election campaign.
"I have a business here, we have set up shop here, laid down our roots and have established ourselves here," he said. "I chose to leave Auckland and wanted to have a better quality of life down here. Going back to Auckland would be a step backwards.
"Phil is head and shoulders the best [mayoral] candidate from anyone who has been announced. His is a safe pair of hands and has so much experience," Mr Coffey said.
Mr Goff has indicated he would stand aside from his MP duties during the final weeks of the mayoral campaign. He will continue in his elected role as the MP for Mt Roskill unless he is successful in his bid for mayor, at which time he will resign immediately.
A Labour Party spokesperson told the Rotorua Daily Post that no decision had been made on a candidate for Mt Roskill should Mr Goff be successful.
"There is a wealth of talent in the electorate and any decision will be made closer to the time."
Former Green Party member and Auckland council employee David Hay is also standing.
Other confirmed candidates are Orakei Local Board member Mark Thomas, right-wing candidate Stephen Berry and activist Penny Bright.