Federal Liberals say they won't support the NDP in its effort to push a private member's climate-change bill through the House of Commons on Wednesday.

The proposed legislation, called Bill C-311, the climate change accountability act, sets strict targets for greenhouse gas emissions and is currently being considered by a House environment committee.

The committee has asked for an extension of 30 sitting days to review the bill, a request that will be considered Wednesday when the House sits.

But New Democratic Party Leader Jack Layton said the delay would undermine efforts to have the bill passed into law before the Copenhagen summit in December.

Layton wants the bill's tougher greenhouse gas emission reduction targets to be in force when Canada sends delegates to the summit, where international leaders hope to forge a successor to the Kyoto Protocol, the global greenhouse-gas treaty ratified by dozens of countries, including Canada.

The bill has passed through two readings in the House of Commons since it was introduced by NDP member of Parliament Bruce Hyer, receiving support from the Liberals and the Bloc Québécois.

Liberal environment critic David McGuinty, however, said the committee needs more time to study the implications of the bill.

"We need to hear more about the American position, the European position, the Chinese position" before considering the bill, McGuinty told CBC News.

Bloc to support bill's passage

The Bloc has agreed to support Layton's motion to speed passage of the bill.

"I think it's not time to discuss about this bill, it's time for action," said MP Bernard Bigras, who is vice-chair of the House environment committee.

Bill C-311 calls for Canada to cut greenhouse gas emissions to 25 per cent below 1990 levels by 2020 and 80 per cent below 1990 levels by 2050. It also gives the government the authority to make regulations to meet the targets, including penalties for contravention.

The Conservative government has pledged to lower greenhouse gases 20 per cent from 2006 levels by 2020.

An identical bill introduced by Layton in the last session of Parliament passed its final reading in the House of Commons in June 2008, but died before making it through the Senate when the election was called in the fall.