The Liberals and Bloc Quebecois have succeeded in allowing a special committee to study the proposed Clean Air Act for another 11 days, amid speculation the Conservatives and NDP cut a deal on the legislation.

Climate change dominated discussion and debate as members of Parliament returned to Ottawa on Monday after a six-week recess.

During question period on Monday, Liberal leader Stephane Dion accused Prime Minister Stephen Harper of denying that climate change exists.

Harper countered by saying his party is taking steps to curb greenhouse gases by offering funding for "eco energy" initiatives, renewable fuels, and making investments in public transit.

While the climate-change issue heated up rhetoric in the House of Commons, the real battle will be waged over the next few weeks in a Commons committee room.

On Monday, parliamentarians on a special legislative committee met to discuss the government's Clean Air Act. After some three hours of wrangling at the committee, the Liberals and Bloc agreed to defer a deadline to March 30 rather than March 19 as proposed by the NDP.

The Clean Air Act is the Tories' key climate-change legislation, and it might be difficult for them to retain control of the minority Parliament if it fails to pass.

Opposition parties and environmentalists have spoken against the current bill, mainly because it contains no short-term target for cutting greenhouse emissions, and no reference to the Kyoto Protocol.

NDP Leader Jack Layton made it clear Monday he will not give up on his position, despite rampant speculation the New Democrats will co-operate with the government to help pass the bill.

"We're already a part of Kyoto and we're darn well going to stay there," he said outside the Commons. "We've always held that position. We've put forward that plan time and time again."

Environment Minister John Baird once again rejected the Kyoto targets in the Commons on Monday, promising the government will announce realistic targets soon.

Baird also indicated he has met with representatives from the Liberals, NDP and Bloc Quebecois in hopes of working together to "drive forward our environmental agenda."

"I don't think any of us want an election this spring," said Baird.

"We've got a big agenda to get through, so we hope we can focus on getting results and real action on the environment and other issues."

The Globe and Mail reported that when the committee met on Monday, the political dynamic quickly began to show itself. The NDP and Tories often agreed with each other and both parties accused the Liberals of stall tactics.

The scene in the committee room echoed the dynamic that saw then-treasury minister John Baird pass the government's centrepiece Federal Accountability Act. Baird was able to pass the ethics bill with NDP support.

Last year, Baird and his senior aides held a secret meeting with the lone NDP MP on the committee, Pat Martin.

There, Baird agreed to support more than 20 NDP amendments if Martin would support the Tories' ethics legislation.

The lone NDP MP in the Clean Air Act committee is Nathan Cullen. The Globe reports that Baird's aides and Cullen's aides are clearly in communication.

The newspaper cites an example when the Bloc Quebecois suggested a timeline for the committee.

One of Baird's officials met in the back of the room with an NDP aide and moments later, a joint NDP-Tory counterproposal emerged.

It's unclear, however, whether the Tories and NDP are cutting a deal on details, or whether they have reached a compromise on larger policy issues.

The Conservatives appear ready to agree to short-term targets to reduce greenhouse gas emissions, a cap on emissions from industrial polluters, tougher fuel-efficiency standards for automobiles, and possibly cuts in subsidies for the oil industry.

Layton has asked for changes in those areas of the bill, in exchange for the support of his party's 29-member caucus.

But Cullen, the NDP's environment critic, dismissed suggestions he had cut a deal with the Conservatives.

With files from The Canadian Press