The Government is "in negotiation" with other parties over the Emissions Trading Scheme, a report on which should have been released last week.
Parties taking part in the select committee inquiry into the ETS were expected to deliver their minority views by the middle of last week.
National wanted to amend the current ETS and had been holding talks with Labour and other parties to find a compromise.
Talks with Labour have stalled and it has emerged that the Maori Party asked committee chairman Peter Dunne to withdraw its minority report.
Maori Party MP Rahui Katene said her party had been negotiating with several parties.
Prime Minister John Key said today the Government was "now effectively in negotiation".
"There's an ETS on the books, it's a very expensive one under Labour, it would mean that quite a number of business in our view would close down. There would be a high price for consumers to pay.
"We want to amend that. Our preferred option is an ETS," he told Newstalk ZB.
The Government still had "options", he said.
It was still unclear when the ETS report would be made public.