The Maori Party has accused Winston Peters of using his state of the nation speech to deliver a "racially divisive diatribe".
The NZ First leader yesterday said the government had been "brownmailed" by the Maori Party into making policy concessions in return for its support for Resource Management Act reforms.
The Maori Party agreed late last year to support the RMA amendments after gaining concessions around consultation with iwi on the management of natural resources.
"The proposed changes are a signal flare to the entire country that the two parties are taking us down the track of separatism," Mr Peters said in his speech to the Orewa Rotary Club.
"We are no longer one people. We are moving towards two separate groups with separate rights."
Mr Peters said all references to the Treaty of Waitangi should be removed from the RMA legislation.
Maori Party co-leader Te Ururoa Flavell says Mr Peters "preached his anti-treaty and racially divisive diatribe" to a largely Pakeha audience to whip up the threat of separatism.
"The changes proposed to the RMA which will require councils to engage with local iwi are a common sense solution to ensuring Maori and the Crown honour their Treaty of Waitangi obligations," he said.
The party's other co-leader, Marama Fox, says Mr Peters was tapping into "irrational fears" that honouring treaty rights took away the rights of others.
"It's ironic that New Zealand First brands itself as the party protecting New Zealand's sovereignty while it's happy to discard the rangatiratanga (sovereignty) of Maori under Te Tiriti," she said.
Mr Peters was speaking at the venue used by former National Party leader Don Brash when he played the race card in 2004 with his highly controversial "one law for all" speech.
At the time, it gave National a big boost in the polls.
Mr Peters used the same words in his speech: "It is now obvious to all that which has long been obvious to New Zealand First and our supporters, and that is that there is only one party that stands for one law for all."