The Green Party says the Government's replacement for the Foreshore and Seabed Act is another land confiscation and the Maori Party should not support it.
The Marine and Coastal Area Bill guarantees public access and restores the right of iwi and hapu to go to court to claim customary title.
The Maori Party says it is the best deal it can negotiate at the moment, but it does not rule out re-litigating the issue in the future.
Greens co-leader Metiria Turei says the Maori Party need to argue that the bill is a win for them - but they will be voting, she says, for a confiscation of Maori land and for Maori rights to be treated in a second-class way.
The Maori Party has painted itself into a corner, Ms Turei says, and will end up supporting an unjust law.
Party has 'copped out' - Sykes
One of the leaders of the 2004 foreshore and seabed hikoi says the bill is a step back for Maori.
Lawyer Annette Sykes, from Ngati Pikiao, told Waatea News the Maori Party has copped out in allowing the bill to go forward in its current form.
The bill is just as discriminatory as Labour's Foreshore and Seabed Act, Ms Sykes says, and in some ways worse, because it gives harbour boards more rights than hapu.
Maori Party MP defends deal
The Maori Party's Waiariki MP, Te Ururoa Flavell, says however that it's the best deal the party could do with the National-led government.
Mr Flavell told Waatea News that the bill addresses many of the key concerns identified by the working party led by retired High Court judge Sir Eddie Durie - though there are still areas where Maori may want to push for change.
The bill was tabled in Parliament on Tuesday.