John Tamihere's statements that Labour's Māori MPs are silenced is a load of nonsense, Labour MP Willie Jackson says.
Tamihere, a former Cabinet minister in Helen Clark's Labour government, is to stand for the Māori Party in Tāmaki Makaurau in this year's election.
He believes Labour's Māori caucus has been ineffective on issues like Whānau Ora and the land dispute at Ihumātao.
Labour MP Willie Jackson said that was a "load of nonsense".
"Māori MP's have every opportunity to talk, John actually doesn't know what the heck he is talking about," Jackson told RNZ.
"We have been working strongly in terms of Ihumātao - some of us have been on the ground the last few weeks trying to negotiate this settlement."
The two are of course familiar with a good head to head - going up against each other in 1999 for what was the Hauraki Māori seat, with Jackson standing against Labour in 2002.
Jackson - who used to co-host a talkback show on Radio Live with Tamihere - said he wished Tamihere the best, but was confident in his party and the work they had done for Māori.
"Good luck to him, we all know what a strong competitor John is. The reality is we are ready, Peeni [Henare]'s ready. We will take the challenges but I don't mind the debate - but don't say that the Māori MP's aren't advocating when that's all we are doing on the ground."
When asked if he would work with the Māori Party - Jackson did not rule it out.
"I will work with anyone that will advance Māori interests, as you know, John and I have worked together many many times over the years for the last couple of decades.
"If you're on the kaupapa, you're on the kaupapa."