OTTAWA - Tom Mulcair is dialling back the NDP's anti-oilsands rhetoric as he prepares for his first visit to Alberta's massive, unconventional petroleum deposits.

The NDP leader is to tour Suncor's oilsands project near Fort McMurray on Thursday.

The visit is akin to walking into the lion's den for Mulcair, who has been lambasted by western premiers for blaming booming oilsands exports for artificially inflating the Canadian dollar and, as a result, hollowing out the country's manufacturing sector -- a phenomenon dubbed the "Dutch disease."

On Monday, the words "Dutch disease" did not cross Mulcair's lips as he discussed his upcoming tour. He seemed to take pains to tone down his rhetoric, which was already much less inflammatory than the diatribes his predecessor, Jack Layton, used to unleash against the poisonous "tar sands."

After flying over the oilsands during the 2008 election, Layton blasted Prime Minister Stephen Harper for refusing to "protect the North from the toxic discharges of his friends in the big oil companies."

By contrast, Mulcair's tour is being organized by one of those big oil companies, Suncor, in what is meant to show a more businesslike, measured approach to the issue.

Mulcair insisted Monday he's not against development; he's only advocating sustainable development. And he stressed that applies not just to the oilsands but to natural resource projects all across the country.

Western premiers and federal Conservatives have accused Mulcair of pitting the resource-rich West against the manufacturing centres in eastern Canada. In that vein, British Columbia's ruling Liberals introduced a motion Monday asking the legislature to unanimously reject Mulcair's assertion that "resource extraction in western provinces is bad for Canada."

But Mulcair said he's never singled out the West.

"You know you cannot find a single statement from me with regard to the West. I notice that some of those premiers are saying this is an attack on the West," Mulcair told reporters.

"What I say with regard to sustainable development applies as much in New Brunswick and it does in British Columbia. It's a vision to include economic, social and environmental aspects every time the government takes a decision."

Mulcair maintains the environmental clean-up costs of developments like the oilsands should be paid by the companies and included in the price of their exports, which would help bring down the value of the Canadian dollar.

His stance is expected to be roundly condemned once again by western premiers who are gathering for their annual meeting Tuesday in Edmonton.

But Mulcair insisted he's not trying to pick a fight with the premiers, after referring dismissively to them earlier this month as Harper's "messengers."

"I've been a provincial politician, I was a minister provincially (in Quebec) so I have nothing against provincial politicians."

Rather, he said his fight is with the federal government which he accused of failing to enforce its own environmental protection legislation when it comes to the oilsands and other resource developments.

Mulcair said he's feeling "not a bit" snubbed by Alberta Premier Alison Redford, who has said she'll be unable to meet with the federal NDP leader as she'll be out of the province Thursday. He is scheduled to meet instead with deputy premier Thomas Lukaszuk, as well as with the mayor of Fort McMurray.

He'll be joined on his oilsands tour by the NDP's lone Alberta MP, Linda Duncan, environment critic Megan Leslie and energy critic Peter Julian.