Canada is to issue new rules to speed up approvals of oil pipelines and other big projects, Resource Minister Joe Oliver said Monday, accusing foreign celebrities of clogging up review processes.

"Environmental and other radical groups," Oliver said in an open letter, "threaten to hijack our regulatory system" to try to delay mining, forestry and energy projects to the point they become economically unviable.

"They seek to exploit any loophole they can find, stacking public hearings with bodies to ensure that delays kill good projects," he said.

They also attract "jet-setting celebrities with some of the largest personal carbon footprints in the world" and "use funding from foreign special interest groups to undermine Canada's national economic interest."

Canada's environmental review system, Oliver concluded, "is broken." "It is time to take a look at it. It is an urgent matter of Canada's national interest."

The minister's announcement comes as hearings are set to begin this week on the Northern Gateway pipeline to bring crude oil from the Alberta tar sands to the Pacific Coast.

More than 4,000 groups and individuals have registered to file submissions before the hearings.

And, according to Canadian media, some US activist groups are bringing the star power of actors Robert Redford, Kevin Bacon and Leonardo Di Caprio, and lawyer Robert Kennedy Jr. to the fight.

Virtually all of Canada's energy exports go to the United States, but after Washington last year delayed approval of a pipeline to carry oil from the tar sands to the US Gulf Coast, focus shifted to China as a new customer.

US groups that campaigned to delay approval of the 1,700-mile (2,700-kilometer) Keystone XL pipeline through the Great Plains are now said to be targeting the proposed Northern Gateway pipeline.

The Northern Gateway pipeline, proposed by Canadian company Enbridge, would transport oil from Alberta's tar sands through nearly 1,200 kilometers (750 miles) of rugged mountain landscapes to Kitimat on British Columbia's northern coast, for eventual shipping to Asia.

Up to 220 supertankers each year would sip from it, one report estimated, and environmentalists say tanker traffic poses risks to a pristine coastline that includes salmon-bearing rivers and the habitat of a rare white bear.