The New Zealand Government has said it will pass a law preventing indigenous Maori tribes from claiming exclusive ownership of the nation's coastline and seabed.
It follows a ruling last week by the Court of Appeal which said Maori tribes could pursue their claim, New Zealand media reported.
The government said the new law will guarantee access to New Zealand's shores to all citizens.
Maori leaders have reacted angrily to the move, which they say violates New Zealand's founding charter, which guarantees Maori land rights.
Maori tribes are currently pursuing claims for exclusive rights to New Zealand's lucrative Marlborough Sounds on the south island.
New Zealand Prime Minister Helen Clark told reporters: "What we are faced with is something never before contemplated, which is [that] an exclusive legal title could be given over New Zealand beaches and sea beds."
Maori leaders say the proposed law contravenes the 1840 Treaty of Waitangi, which guaranteed Maori "full exclusive and undisturbed possession of their lands and estates, forests and fisheries".
Maori constitutional expert Moana Waitangi said the government's plan could set back race relations by years.
He warned that Maori would take to the streets to protest against the new law.
The Marlborough Sounds are used for commercial operations, such as marine farms, and help bring in millions of dollars in tourism each year.
Under the proposed law, Maori would be able to use the coastline for fishing, but would not be able to deny access to anyone.
Maori, who number 530,000 out of New Zealand's population of four million, are among the poorest sections of society.
Recent claims by Maori for rights to gas and oil fields have created bad feeling with non-Maori in the country.