The Labour Party has reaffirmed its promise to tax animal emissions from 2013, if it becomes the next Government.
Labour's environmental spokesperson Charles Chauvel outlined what he called the party's single biggest environmental promise this election at Auckland's Waterfront on Sunday.
He says nearly half of New Zealand's greenhouse gas emissions come from grazing animals and it's environmentally irresponsible to leave agriculture out of the emissions trading scheme.
"When you have basically half your emissions unaccounted for, where there's no incentive to reduce them, in fact where every incentive is to grow them, because that's what we're seeing with an increase in dairying at the moment, along with the effect that that has on our water quality, of course it has to be brought into the scheme and regulated, and it is a very, very significant promise", he said.
Mr Chauvel says the 2013 entry date for agriculture into the ETS means farmers would initially pay 10% of their 2005 agricultural emissions, plus any growth since then.
Mr Chauvel says National's decision to delay agriculture into the ETS would cost $800 million over five years.
He says that money would be used to fund private-sector research and development.