Canada on Tuesday unveiled plans to simplify the way it reviews major economic projects, but the opposition charged that the changes would gut the country's environmental protection laws.

Natural Resources Minister Joe Oliver said the new process will "help prevent the long delays in reviewing major economic projects that kill potential jobs and stall economic growth by putting valuable investment at risk."

But the opposition New Democrats and environmental activists said the new process puts business interests ahead of local and environmental concerns, and will result in weaker environmental standards.

"These new measures will severely gut environmental protection," said New Democrat MP Megan Leslie.

"After slashing funding to the Canadian Environmental Assessment Agency, (the Tories) are now saddling it with the obligation to do more complex reviews, faster, with fewer resources."

Canada's resource sectors employ an estimated 760,000 workers nationwide, and represent a large segment of the economy. The mining and energy sectors alone account for 40 percent of exports.

Over the next decade, more than 500 projects representing over Can$500 billion (US$500 billion) in new investments are proposed across Canada, according to the natural resources ministry.

Reviews of projects such as oil and gas pipelines, new mines or power plants under various Canadian legislation have typically included assessments of impacts on fisheries, navigation, wildlife, soil and nuclear safety.

The new rules will require only one review per project by recognizing provincial assessments as substitutes for overlapping federal checks.

The number of federal organizations responsible for reviews will be consolidated from more than 40 to three: the Canadian Environmental Assessment Agency, the National Energy Board and the Canadian Nuclear Safety Commission.

The changes also set time limits for regulatory hearings and assessments with 24 months given for panel reviews, 18 months for National Energy Board hearings and 12 months for standard environmental assessments.

Conservative Prime Minister Stephen Harper has lamented that projects could be delayed indefinitely under the previous rules as activists piled on submissions for review panels to consider.

"This is saying the federal government has no interest in protecting the environment," Green Party leader Elizabeth May told public broadcaster CBC.

"This is democracy and you're not supposed to put timelines on it."