Parliament looks set to be debating foreshore bills for years to come after Labour pledged today to repeal the Government's legislation when back in power.

Labour leader Phil Goff said his party was pulling its support for the new Marine and Coastal Area (Takutai Moana) Bill.

That leaves the legislation - a result of a Government deal with the Maori Party - with a more precarious future with only a two vote majority to pass it with.

The Maori Party formed over discontent with Labour's Foreshore and Seabed Act which the new bill is replacing but one of its MPs - Hone Harawira - is voting against it.

The bill returns to Maori the right to seek customary title over parts of the coast through the courts or through negotiation with the Government.

The main concern of dissenting iwi and Mr Harawira is that the test for that is uninterrupted use and occupation since 1840, which they say is too high and will rule out many applications.

Labour, the Greens, ACT, Jim Anderton, Mr Harawira and independent MPs Chris Carter make up 59 votes against the bill. National would have its own 58 votes, plus four from the Maori Party and one from United Future's Peter Dunne to give it 63 votes in the 122-strong house.

Maori Party co-leader Tariana Turia said she was confident her party would back the bill despite its negative reception at select committee hearings and she was seeking changes on the test requirement.

"I would say they've (Labour) been watching all the representations that have come to the committee, they think that every Maori in the country is against it, but what they don't realise is there's not one Maori in the country that's forgotten what they did."

Mr Goff said negative submissions to the select committee, division within the Maori Party and comments by Mrs Turia and others that the bill may be revisited in future showed it would not be an enduring settlement.

If that proved to be the case Labour would repeal it.

Attorney General Chris Finlayson said Labour's mistake was to pass the original law. He was confident the new bill would be enduring.

"I shouldn't think the Labour Party would ever want to revisit this situation again."

Mr Goff said Labour would work with other parties on alternative legislation which would retain free access to beaches, recognise Maori customary rights and allow Maori to take their claims to court.

Labour has consulted some parties about the idea and Mr Goff said that included Maori Party co-leader Pita Sharples who would still vote for his own bill but was open to ongoing dialogue.

Labour MP David Parker said the major complaint of iwi was that the Government's bill extinguishes rights through threshold tests, that should be decided by court.

"There are extreme views on both sides of the debate that are wrong, the truth lies somewhere in the middle... Let people have their day in court and argue for their rights and if they've got them we will recognise them but we will preserve access."

Putting claims in the hands of the courts would de-politicise the issue and politicians would not get involved as long as free access was enshrined in law.

ACT said its preference was to scrap the current bill and repeal the 2004 Act and leave it to the courts to decide what happens. However a spokesman said the party was open to discussions with Labour about its proposal.

Green Party co-leader Metiria Turei was pleased that Labour changed its position.