The push to change the flag could spark a Treaty claim – with some Maori unhappy about a lack of consultation.

Ngapuhi elder Patu Hohepa says John Key’s speech at Waitangi on Friday was the first engagement with Maori on the flag referendum.

"Nothing has ever come out to us except through newspapers, radio and television. It's sad."

Dr Hohepa warns concerns could be raised at the Waitangi Tribunal.

"I think there would be action from now on for the recognition of the flag, there's already been some submissions based on that, but we'll certainly now put that all together so he can understand where we are coming from."

Patu Hohepa says many in Maoridom would like to see a return to the United Tribes flag – which was New Zealand’s first flag, in 1834.

Mr Hohepa was especially critical of John Key’s now-abandoned suggestion of a black flag with a silver fern.

"Black being a sign of death in all nations, and silver being a sign of prosperity of those, the 10% who hold the wealth of the world, that should never be thought about as the flag of New Zealand."