A Northland Maori leader says Waitangi Day could be more volatile than ever. 

Prime Minister Chris Luxon's decided against attending celebrations at the Treaty Grounds. 

He says he'll join events in other parts of the country - and is expected to send ministers in his place.

Luxon and the coalition have faced mounting pressure over ACT's Treaty Principles Bill.

Waitangi National Trust chair Pita Tipene says he's wondering where else Luxon could rather be. 

"Any Waitangi Day is a cauldron - let alone what's going to happen next year, given the Treaty Principles Bill and everything else that's going on."

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