Nova Scotia Premier Rodney MacDonald has taken his campaign against the federal Liberals' proposed carbon tax to the internet.

The provincial Tory caucus has included a calculator on its website to show how much more people might pay on heating oil were a carbon tax to be implemented.

According to the Conservatives' online calculator, someone who paid $3,000 for heating oil last year would have to pay an additional $420.

MacDonald said he opposes the the carbon tax, under the Liberal Party's Green Shift plan, because it punishes provinces like Nova Scotia that rely heavily on fossil fuels.

"It will hurt Nova Scotians, it will hurt Nova Scotia businesses," MacDonald said Thursday.

"I want to make sure that all federal parties are aware that this government, and I as premier, will not stand for such a tax."

Nova Scotia Liberal MP Scott Brison was quick to criticize MacDonald's opposition to the proposed carbon tax.

Brison, the MP for Kings-Hants riding, accused MacDonald of trying to discredit a carbon tax in order to please the federal Conservatives.

"Rodney MacDonald is more interested in being Stephen Harper's lap dog in Nova Scotia than he is in defending the interests of Nova Scotians," Brison said Thursday.

"He's only trying to feather his own nest after the next election when he loses and needs a patronage appointment from Stephen Harper."

MacDonald's minority government, elected in 2006, has a narrow three-seat edge on the NDP in the 52-person provincial legislature.

Brison accused MacDonald of addressing only some of the facts behind the Liberal carbon tax plan.

Under the proposed plan, Brison said, Nova Scotians would pay an average of $240 more on their annual home heating oil bill after four years. But people would also receive tax cuts to offset that increase, he added.

Brison has invited MacDonald to have a public debate on energy issues, but the premier has declined.