In an effort to fast-track lucrative energy and mining projects, the federal government will streamline its environmental assessment process and focus only on major, high-risk developments, such as the Northern Gateway pipeline, CTV News has learned.

Government sources say complex regulatory requirements involved in every environmental review will be replaced with a much faster process handled by only three government bodies instead of dozens of federal authorities whose work is often duplicated.

Environmental reviews will now have firm deadlines to approve or reject proposed resource projects within two years, CTV's Ottawa Bureau Chief Robert Fife reported.

Natural Resources Minister Joe Oliver will formally announce Ottawa's plan on Tuesday.

Under the current system, some resource projects could take years to approve because of delays and bureaucratic wrangling.

Smaller, low-risk projects will no longer be subject to such federal reviews. Oversight will be handed over to the provinces, prompting criticism from environmental groups who say the reforms will put Canadians at risk.

"It's really dragging us backwards to allow big oil to get its way as fast as possible," said Gillian McEachern, deputy campaign director with the Environmental Defence, an activist organization.

The Conservatives promised in the federal budget to speed up the environmental review process, and Harper was using that pledge as a key selling point to Latin American investors over the weekend at the Summit of Americas in Colombia.

It's something oil and mining executives have been aggressively lobbying over the years, saying faster project approvals will translate into more oil, gas and mining industry jobs.

"We think that making the system more efficient is going to help us attract the capital we need to get these projects going," Travis Davies of the Canadian Association of Petroleum Producers said in an interview with CTV News.

The Mining Association of Canada said a faster review process could mean "hundreds of thousands" of new jobs.

In 2010, natural resource sectors employed more than 760,000 people across the country. More than $500 billion in new projects is planned over the next decade.

"By developing Canada's abundance of natural resources responsibly, we can seize the moment for this country," a senior government source told CTV News.

"The world wants our resource products and in turn, Canadians will reap the rewards of jobs, investment, economic growth and prosperity for generations, while we maintain the highest possible standards for environmental protection."

But critics say the planned changes are simply a government "gift" to the energy sector.

Canada's Commissioner of the Environment Scott Vaughan has already criticized Ottawa for failing to protect aging pipelines from spills and explosions. He said some energy companies haven't even submitted emergency response plans in case of pipeline malfunction or damage.

Emergency procedures that are already in place are often flawed, Vaughan said.

But government officials insist the streamlining of environmental reviews won't be done at the expense of the environment or thorough scientific and safety evaluations.

The Harper government is promising a 50-per-cent increase in pipeline inspections and tougher fines for violations, ranging between $100,000 and $400,000.

Still, many questions remain, Fife reported Monday, including how the government plans to define major resource projects and how individual provinces will be involved in their approvals.

Fife also pointed out that natural resource projects, especially those that involve the use of Aboriginal land, are often challenged in court, adding another layer of complexity to environmental reviews.