The announcement that Pita Sharples will stay on as Maori Party co-leader and stand in next year's general election could tip voters in his Tamaki Makaurau electorate towards Labour.
Dr Sharples told Te Karere on Thursday he doesn't intend to give up the co-leadership position and will contest the 2014 election.
Dr Sharples won Tamaki Makaurau over Labour's Shane Jones by fewer than 1000 votes in 2011.
Mr Jones told NZ Newswire Dr Sharples' decision to stay on shows "he is not only irrelevant, it shows that Tamaki Makaurau will definitely be a Labour seat".
"I think it's sad that Pita, who was born during the Second World War, wants to hang around when there's an entirely new generation coming through with a new blend of thinking," he said.
"After being muzzled last year by the government, he seems to have discovered his voice. But he's fighting his own people as opposed to fighting the true source of Maori socio-economic political problems, which are the policies of the current government," Mr Jones said.
Dr Sharples' fellow co-leader Tariana Turia has already announced she will retire from politics at the 2014 election, but has indicated she may give up her leadership role sooner than that.
The party's third MP, Te Ururoa Flavell, had been tipped as Mr Sharples' likely successor.
However, Mr Flavell has previously said he may not stand at the next election if Dr Sharples doesn't give up the reins.
All three of the Maori Party's MPs have been in parliament since 2005, after the party formed when Mrs Turia quit the Labour Party over the Foreshore and Seabed Act.