New Zealand's planned carbon trading scheme, the first cap-and-trade market outside Europe, is expected to survive even if Prime Minister Helen Clark loses a national election on 8 November.
But the carbon trading scheme, scheduled to start in 2009, would face a host of amendments if the opposition National Party, which leads the Government in opinion polls, takes office.
A National government is likely to give key industry sectors more time to reduce emissions, said regional law firm Minter Ellison, which has studied the trading system.
"It would still be a good carbon trading system, there will still be changes to behaviour but it will give certain sectors more opportunity to amend ways they conduct their business," Matthew Andrew, head of Minter Ellison's climate change group in Wellington, said on Friday.
"National will perhaps be more generous around the phase-in time to give key industry sectors time to manage their emissions down and find new ways of reducing emissions going forward."
Under The Climate Change (Emissions Trading and Renewable Preference) Bill, trading of carbon credits begins in 2009, with all industry sectors, including agriculture which produces 50% of emissions, covered by 2013.
Those that breach their limit will have to buy credits from users that produced emissions below their ceiling.
The centre-left Labour Party that leads a minority government, pushed hard to get the climate change law passed on Wednesday, before its term in government expired, and was forced to introduce 785 amendments to win support.
The bill faced a rocky path, with the minority-led government forced into months of negotiation with the Greens and New Zealand First parties to win majority support.
Labour has said it wants New Zealand, an agricultural-based economy with a "clean, green" international reputation, to be carbon neutral by 2050.
But the National Party has said it would abandon the Government's carbon-neutral policy, aiming for only a 50% reduction in emissions from 1999 levels.
National has also said it would look to reduce the amount of revenue accrued by the Government under the scheme, and reduce the burden on major industries, which it said will result in a loss of jobs for New Zealand.