The first act in Labour's bid to rejuvenate its ranks for next year's election will be in Napier, where list MP Russell Fairbrother, 62, faces a challenge for selection by Stuart Nash, 39.
And the gloves are off, not least over who at the top supports them.
Mr Nash says he has been "encouraged" at high levels to stand but won't confirm whether the encouragement came from Prime Minister Helen Clark.
Mr Fairbrother, in turn, claims the Prime Minister's backing and says he is confident of winning selection.
Mr Nash said that National had "walked all over Russell" at the last election when National candidate Chris Tremain won the seat from him.
"I don't think Russell has shown the energy to win that back for Labour. It's not because of his age. It is just that in the five years he has been there he has never shown the energy necessary to win that back."
Mr Fairbrother said that the challenge had "energised" the electorate committee.
Mr Nash: "My reaction is if it took five years and an election loss of a safe seat and me coming down to get you gee-ed up, then maybe you should have got gee-d up about five years ago."
Mr Fairbrother said he did not lose support in Napier - a traditional Labour electorate - but the right vote massed around Mr Tremain.
He believes he was disadvantaged at the last election by the Exclusive Brethren, who distributed pamphlets against him and push-polled. He also ran a party-vote campaign as opposed to National's more individually based campaign.
Mr Fairbrother says that he will not seek a place on the Labour list next year.
Mr Nash stood for the first time in 2005 in the Epsom seat. He has been director of strategic development at the Auckland University of Technology but is now moving to Napier, where he was brought up.
Under Labour's selection procedures, head office has three votes, the Labour Electorate Committee has three and one of the selectors is voted from the floor.
Selections won't begin until final boundaries are out on September.
Party president Mike Williams said in May that up to 10 present MPs might retire next year.
Helen Clark has said the sitting MPs cannot expect the same protection of a preferential list place that almost all have had for the past two elections.