The NDP can usually count on having the environmental vote locked up -- but not this year.

The party is facing harsh criticism from environmentalists, including the David Suzuki Foundation and Pembina Institute, for wanting to scrap the carbon tax.

And the Liberals are jumping at the chance to paint themselves as the new green champions.

Environment minister and Liberal MLA Barry Penner visited the McGillivray Slough along the Fraser River on Monday, armed with a big election-eve announcement.

With industrial development nipping at the Fraser River's edges, the slough's 915 hectare area of important fish and wildlife habitat will be protected.

"In my view, that is one of the most important conservation initiatives in all of Canada so any progress to protect key habitat is great to see," said Mark Angelo of The Heart of the Fraser environmental group.

This is high praise for a party that isn't usually known for its environmental policies.

So when the NDP announced last week it would scrap the carbon tax if elected the Liberals saw an opening.

"I can't understand why they are putting short-term politics ahead of dealing with climate change. It's just wrong. It's wrong from an economic perspective. And it's wrong from an environmental perspective," said Penner.

The Pembina Institute, one of the leading organizations for sustainable energy, agrees and slammed the NDP for a policy it said is economically irresponsible.

"If we lose the carbon tax, it will be very difficult to get it back where we are for the path for climate change," said Karen Campbell, one of the institute's directors.

But NDP leader Carole James stands by her platform.

"We certainly agree to disagree with the environmental movement around the government's carbon tax. We believe a bad tax is a bad tax and it's very clear the carbon tax isn't working," she said.

The Liberals hope this is an NDP misstep as the election campaign begins.

With a report by CTV British Columbia's Leah Hendry.