A leading Maori lawyer says that it will be practically impossible for Maori to seek customary title to the foreshore and seabed.
The National-led Government has reached agreement with the Maori Party on repealing the 2004 Foreshore and Seabed Act and moving it from Crown ownership to the public domain.
Under the proposed legislation, Maori will have the right to claim customary title by applying to the High Court.
But lawyer Moana Jackson says it will be almost impossible to gain customary title, because iwi and hapu have to prove uninterrupted possession of the land, and that will be hard, as much of the land was in Crown ownership after 1840.
"The standard that has been set for proving customary title is so high that it is practically impossible to meet."
Another lawyer, Prue Kapua, says the cost of taking a case to the High Court is also a barrier for iwi and hapu.
She says they would have to have a relatively clear cut case in order to spend what are often limited resources, such as treaty settlement money.
But both lawyers say the proposed act is better than leaving it as it was.
Big economic opportunities foreseen
On Tuesday, Waikato-Tainui's governance board chairman, Tukoroirangi Morgan, said iwi that successfully claim customary title over the foreshore and seabed will own the minerals under them and the right to mine them.
Mr Morgan said the law change will herald big economic opportunities for iwi. He says customary title is just as powerful as freehold title, except it can't be alienated or sold.
Treaty Negotiations Minister Chris Finlayson says that when an iwi can prove customary title to an area, it will own the minerals underneath, with the exception of gold, silver, petroleum and uranium, which are nationalised.
But the Minerals Industry Association says removing the seabed from Crown ownership will cause uncertainty and deter investment.
Association executive director Doug Gordon says that it will undermine New Zealand's status as a sovereign nation, and that there's a risk iwi will jeopardise development with demands for excessive royalties or even veto it.
Last-minute attempt on court access
Under the agreement, existing Maori and Pakeha private titles will not be affected - nor will public access and existing fishing and navigation rights.
The Maori Party made a last-minute attempt, though, to get the Government to make it easier for iwi to go to court over foreshore and seabed matters.
While the Government's proposal allows iwi and hapu to go to the High Court to claim customary title, the party believes the test they must pass to take court action is too high.
Mr Key says however that that hasn't changed and that iwi will still have to prove they have had exclusive use and occupation of a particular part of the foreshore and seabed since 1840 to meet the test.
The new legislation is expected to be passed by the end of the year.