The Conservative government has considered abandoning some of the greenhouse gas reduction goals set out in its 2007 green plan and allowing weaker targets for the oil and gas sector, documents obtained by CBC News suggest.

The proposal raises questions about how the Tories could cut overall greenhouse gas emissions by 20 per cent by 2020 — a target they insist they can reach — while weakening the targets in the oil and gas sector.

CBC News has obtained draft documents that were prepared for presentation to Prime Minister Stephen Harper's cabinet in the weeks leading up to the United Nations climate change summit in Copenhagen. The documents outline a working draft position of Canada's stance on emissions targets.

The draft proposal talks about harmonizing its approach to cutting greenhouse gases with the United States.

It compares the Conservatives' 2007 green plan, called Turning the Corner, with U.S. legislation (the American Clean Energy and Security Act) passed by the House of Representatives and suggests the targets of Canada's plan are more stringent.

It says that Canada, when setting targets, must take into account that its oil and gas sector will show greater growth than the U.S, in part because of the oilsands.

The draft proposal suggests Canada should set new targets that would be lower than what was originally proposed by the Conservatives.

For example, the proposal suggests that the oil and gas industry would have to cut 15 megatonnes of emissions, rather than 48 megatonnes under its Turning the Corner plan.

It also says projected growth in greenhouse gas emissions from the oilsands in northern Alberta will be 165 per cent by 2020 and proposes to cut that growth — not emissions — by 10 per cent.

The government draft documents make the argument that the U.S. bill gives smaller targets to trade-sensitive sectors, such as manufacturing. It suggests the Canadian oil and gas sector, including the oilsands, deserves the same treatment.

That last proposal will not go over well in the U.S., said John Coequyt of the Sierra Club in Washington, D.C.

"Importing oilsands has been a big concern among many legislators, and it has certainly been a major concern among the environmental community, and we would definitely not want to agree to a climate bill that gives preferential treatment to that practice," he told CBC News.

Coequyt said the measures proposed in the draft documents to harmonize Canada's emissions-cutting with the U.S. make no sense.

"Almost all of those things were not done in the U.S., and the Senate is not talking about doing them, so I have to say I found it almost comical," he said.