OTTAWA — The Conservatives shifted into the comedy zone today as they continued to poo-poo Liberal Leader Stephane Dion's anticipated `Green Shift' plan for the environment.

Dion is to announce details of the plan Thursday, hoping Canadians will buy into the notion that shifting much of the federal tax burden onto carbon fuels will help cut greenhouse-gas emissions.

But Conservative MP Jason Kenney says if the Liberals get their way, Canadians will be `shift out of luck.'

Kenney told the Commons today a slogan taxpayers might adopt for the carbon tax that's included in the plan could be `shift happens.'

Kenney says that's also the Liberal message to the 2,000 Air Canada employees who will soon lose their jobs.

The air carrier announced the cuts this week as it struggles with high fuel prices.