Labour MP Shane Jones has been told off by the Ratana Church for becoming embroiled in a row over the legalisation of marijuana during last week's celebrations.

Jones clashed with the leader of a pro-cannabis party after he made an impassioned speech in favour of the drug's legalisation on Friday.

Speaking at the celebration of prophet Wiremu Potiki Ratana's birthday, an event that marks that start of the political year, Fred Macdonald of the Aotearoa Legalise Cannabis Party (ALCP) argued that legalising cannabis would earn more revenue for the Crown and see fewer people imprisoned. Macdonald said the drug was used as a medicine in the time of Jesus Christ.

"Just get on with it, stop making our cannabis convicts political prisoners because that's what's going on. The war on drugs, it's just a whole lot of bullies . . .," Macdonald said.

Jones, who was in the audience for the speech, then launched a rebuttal when it was his turn to speak, saying drugs and alcohol were a major problem in Maori communities and a religious celebration on a marae was not a place to associate Jesus with cannabis, praise its potential or argue for decriminalisation.

"I wanted to send a message to all the visitors and to Ratana: do not allow your powhiri to be diminished by some half-stoned creature from Macdonald's farm," he said.

It was particularly "galling" that a Pakeha man could make such a speech on a marae when Maori women were not accorded that privilege, he said, adding "the vast majority of the Maori there were offended".

Jones said he had been taken aside by Ratana followers and thanked for his actions.

But Church spokesman Andre Mason said he was disappointed in the actions of both men and defended Macdonald's right to speak his mind, even if his views were not shared by everyone there.

"That was very inappropriate of Shane doing that. This is not a normal marae like every other marae , . . .This is a place of freedom of speech and he was right to share his thoughts, maybe it would've been a bit long but he shared he thoughts."

Macdonald had made some valid points and he was "disappointed" with those Ratana members who voiced their opposition, he said.

Macdonald said later he believed he had support in the crowd and rejected Jones' criticisms.

"He attacked me personally . . . He has his right to freedom of speech the same as I do," he said. "Shane did not show respect to the people of Ratana. He didn't show respect to me, I don't care, that's politics, I got my message out."