After years of debate New Zealand is set to have a working emissions trading scheme (ETS) in 2010.

The centrepiece of climate change policy will come into force after National and the Maori Party today reached a deal to amend the existing ETS put in place by the outgoing Labour government.

The original ETS was put on hold by National and the amendments water down parts of it and further delay many industries facing the full cost of their emissions, but Climate Change Minister Nick Smith said it was an "important first step".

Dr Smith said without the deal the ETS would have been put on hold until 2011.

The deal as announced makes little difference to the design of the ETS as put forward by National earlier this year, however it does soften the blow for sectors and groups with large Maori representation.

Under the deal:

* Another $24 million will be spent on insulating the homes of 8000 low income people;

* A Treaty of Waitangi clause will be inserted in the ETS legislation giving the Crown the obligation to consult Maori on ETS regulations;

* Iwi who felt the ETS unfairly undermined their treaty settlements will get the rights to plant 35,000 hectares of crown land and claim the carbon credits worth an estimated $25 million to $50 million; and

*A tree planting incentive policy will be reviewed.

Prime Minister John Key said the ETS would balance economic opportunity with environmental responsibility.

Maori Party co-leader Pita Sharples said the deal and the ETS would benefit all New Zealanders.

Dr Smith said the amended bill would be passed in Parliament this week with the support of the Maori Party and Peter Dunne.

Political parties would be briefed on the deal and the ETS amendments tomorrow.

Once the law was passed detailed regulations would be drawn up and the ETS would start working in July next year.

The ETS will eventually bring all sectors of the economy under a regime designed to reduce greenhouse gas emissions through a carbon trading scheme.