The Maori Party has warned new legislation replacing the Foreshore and Seabed Act is unlikely to bring the controversy to an end.
The Marine and Coastal Area Bill would restore the right of iwi and hapu to go to court to claim customary title, but Maori would have to prove exclusive use and occupation of the relevant foreshore and seabed area since 1840.
The Maori Party will vote for the bill, although its Te Tai Tokerau MP, Hone Harawira, will vote against.
Prime Minister John Key is confident the bill will resolve the controversy over the foreshore and seabed despite Mr Harawira's refusal to support the legislation.
But while Mr Harawira's fellow Maori Party MPs will vote for the bill, they are not unabashed supporters of it.
Maori Party co-leader Tariana Turia disputes Mr Key's belief it should bring the controversy to an end, saying others might decide to push for further changes in the future.
Her fellow co-leader, Pita Sharples, says he is not happy with everything in the bill and shares some of Mr Harawira's concerns.
The bill is due to have its first reading in Parliament on Tuesday.
PM welcomes opposition
The Prime Minister on Tuesday welcomed news that Mr Harawira will vote against the new legislation, saying it is confirmation the Government has got the legislation about right.
But Labour Party leader Phil Goff says Mr Harawira's decision raises questions about the bill.
He confirmed Labour would vote for it to be referred to a select committee for further consideration.
Bill not what Maori want - Harawira
Mr Harawira says the Government has done the right thing by restoring the right to go to court, but told Waatea News that making the court test so tough was hardly a restoration of justice.
He says the Marine and Coastal Area Bill is not the substitute Maori want for the Foreshore and Seabed Act.
Mr Harawira says the Maori Party will probably vote for the bill after its first reading, but wants to see extensive changes at the select committee stage.
He told Waatea News that Attorney General Chris Finlayson was not able to deliver on the promises he was making to Maori during the consultation process.
"I think that he was prepared to go where his colleagues were not prepared to go. I don't think his colleagues were prepared to back him on it."
However, National list MP Hekia Parata says the bill reflects the extensive consultation that went into it.