Prime Minister Stephen Harper dismissed Liberal Leader Stéphane Dion's plan to tax carbon emissions as a "foolish and unnecessary policy" on Wednesday, saying it's nothing more than a cash grab for a government.

Harper was asked what role the government could play in cushioning the impact of high oil and gas prices on consumers. 

He said that beyond providing some tax relief — something he said his party has done with GST and income tax cuts — the government can have little impact on lowering gas prices.

"But I think what we don't need right now when we do face rising gasoline taxes and rising taxes on energy products are governments to come and specifically impose carbon taxes on our economy," Harper told reporters in Beamsville, Ont.

"We think that is a foolish and unnecessary policy that is being proposed by our opposition."

Dion has revealed few details about his carbon tax proposal, saying only it would involve shifting taxes toward things Canadians want less of: pollution, greenhouse gas emissions, smog and waste.

But Harper said the best way to reduce greenhouse gas emissions is through regulating large industrial emitters.

"If what you really want is to get money for the government and claim that you're trying to reduce emissions, then you impose carbon taxes. But that's not a position this government is going to take."

'Lower costs for consumers generally'

Harper said that in the 2004 election, the Tories committed to taking off 0.7 per cent off the excise tax on gasoline.

But he said after that election, they decided broader tax relief for consumers would be better for Canadians.

"We also concluded that the ability of a government to affect the price of gasoline per se is so small that it is not worth doing. What you really got to do is lower costs for consumers generally."

Commenting on the economy, Harper said sectors of it are having some difficulties, that it has "slowed somewhat" and that some Canadians are feeling the pinch.

But he added that, generally speaking, the Canadian economy is in "pretty good shape," particularly in comparison to major Western economies.

Harper said there continues to be growth, albeit reduced, and that the unemployment and inflation rates continue to be low.

He said there are some concerns and challenges, but "we don't want to panic."

"Now is not the time to start spending like drunken sailors, to start running massive deficits, to start raising carbon taxes all over the economy because somebody thinks we should do something."