Mr Turnbull also faced fresh problems with his Senate leader, Nick Minchin, a climate hardliner, again making provocative comments.

Senator Minchin told Sky News he didn't know how anyone who had studied the science could think the climate issue was settled, and the issue was "manna from heaven" for deep-green groups that were hostile to many of the things for which Western society stood.

He said he would abide by whatever the party room decided but dodged a question on whether he would abide by what shadow cabinet agreed on. He said the Government would have to come "a long way" towards meeting the Opposition's amendments before the party room would consider supporting the bills, and accused the Government of breaching good faith negotiations by announcing its concessions on agriculture pre-emptively.

With negotiations possibly stretching into next week, MPs at the Coalition parties meeting complained they wouldn't have enough time to consider any proposed deal, while some want it to go to the party room before the shadow cabinet considers it.

The hardliners at the meeting included six Liberals and four Nationals. Three Nationals - their Senate leader Barnaby Joyce, Fiona Nash and Ron Boswell - said they would vote against the scheme, regardless of what the party room decided. Another National, John Forrest, said the bills should be killed.

Liberals Mathias Cormann, Wilson Tuckey, Dennis Jensen, Mitch Fifield and Bronwyn Bishop called for checks to prevent the shadow cabinet forcing a deal on a reluctant party room.

Negotiator Ian Macfarlane said he and Climate Change Minister Penny Wong wanted the talks finished by Monday but could extend to mid-week. The Government has agreed to exclude agricultural emissions indefinitely, but Mr Macfarlane said there had not been all that much done on other issues.