A deal worth up to $50 million with five iwi to gain Maori Party support for the Government's emissions trading scheme has been criticised as giving special treatment to some tribes and doing little to help Maori households.

The Maori Party yesterday gave its support to passing the revised emissions trading scheme into law after securing the iwi deal and other gains.

The scheme is expected to be passed under urgency in Parliament this week, before ministers travel to Copenhagen for UN climate change talks.

Part of the deal allows Ngai Tahu and four other iwi to plant trees on 35,000ha of Department of Conservation land and keep profits from the carbon credits.

The deal will last for 70 years and is valued at $25 million to $50 million, depending on the price of carbon.

The agreement also allows for more Crown/iwi partnerships in tree planting on conservation and Maori land.

The Government has also agreed to include a Treaty of Waitangi clause in the bill, securing specific rights of consultation.

Labour leader Phil Goff said the concessions the Maori Party had gained would give Maori companies preferential treatment which other forestry companies would not get.

The deal gave little to most Maori, benefiting only a "handful of iwi".

Prime Minister John Key denied the deal for the five iwi amounted to preferential treatment, and said all other Maori forestry interests would be treated the same as all foresters.

The Government had also ensured that public access to the conservation land was maintained.

He said the deal came at no direct cost to the Crown and was an "elegant" solution to the possibility of court action by the five tribes.

The iwi had claimed that relevant information was withheld from them when they bought forestry land for conversion to farming.

Goff: Iwi forestry deal does little to help most Maori

Such court action could have made the Crown liable for up to $138 million.

Ngai Tahu kaiwhakahaere (chairman) Mark Solomon said the compromise was an innovative solution to the stand-off between the iwi and Crown about information it was given when buying its settlement forests.

"It is a day where the ledger is made even," Mr Solomon said.

The issue has been a difficult one for the Maori Party, which has opposed emissions trading schemes because of the extra burdens it believes they would place on lower-income households.

Co-leader Pita Sharples said the party had gained meaningful changes for lower-income households, including a $24 million boost to the home insulation scheme.

National's changes will give heavy-emitting industries, including agriculture, a longer time before they have to bear the full obligation of their emissions.

Climate Change Minister Nick Smith said the scheme balanced the concerns of households and businesses with the need to ensure NZ "does its fair share" to combat climate change.

Mr Goff said National's new scheme was "riddled with privileged deals" for groups of polluters.

It would significantly reduce the effectiveness of the scheme Labour had set up, and would put large costs onto future taxpayers.

*Treaty of Waitangi clause in ETS bill will ensure iwi consultation on future changes to the law.

*$28 million extra for home insulation scheme to help 8000 low-income homes.

*$25 million to $50 million tree-planting deal for five tribes.

*Partnerships for tree planting on Crown and Maori land.

*Fishing allocations will go to quota-holders.

*Two iwi representatives to accompany minister Nick Smith to Copenhagen talks next month and possibly to later international talks.

*Scrapping of Enviro-Schools programme to be reviewed.

*Maori Party to be consulted on wider environmental issues.