The New Democrats are asking the Conservative government to split its omnibus bill into several pieces of legislation so that proposed changes to environmental and natural resource laws can be scrutinized.

The Conservatives have limited debate on their budget bill -- known as invoking closure -- and included new provisions to speed up the environmental review process for major projects.

The closure motion allows for about a week of debate on the omnibus bill, which is more than 420 pages long.

The legislation includes amendments to about 60 laws, eliminates at least six others and rewrites the Canadian Environmental Assessment Act. Reforms to Old Age Security and employment insurance are also included in the bill.

"Our Parliament is being asked to vote blind, gutting environmental protections, ripping up the Fisheries Act, eliminating entire laws," NDP MP Nathan Cullen said in the House of Commons Monday.

"Asking a single committee to review this bill will mean that it won't get the scrutiny that it deserves….there in no transparency, no accountability."

NDP MP Peggy Nash called it "a Trojan horse of a bill," while Green Party Leader Elizabeth May has referred to it as "420 pages of omnibus abuse of parliamentary process."

But Natural Resources Minister Joe Oliver said there will be plenty of debate before the bill is put to a vote.

The Conservatives argue that far-ranging bills of this nature are not new and that they're allowing more debate than the Liberals did on any of their budget bills.

They also say they are devoting more time to debate at second reading than ever before on a budget implementation bill.

"The need for this legislation is urgent," Oliver told reporters before heading into question period Monday. "The world will not stand by and wait as Canada endlessly deliberates the merits of its resource potential and squanders its legacy."

Government House Leader Peter Van Loan also said the budget bill is critical for job creation and economic stability.

Environment groups said they are prepared to tackle the government on the bill along with opposition parties.

A number of groups, including the David Suzuki Foundation, World Wildlife Fund, Greenpeace and the Sierra Club, launched an ad campaign Monday called "Black Out, Speak Out" that urges Canadians to darken their websites June 4.

A full-page newspaper ad with a black background published Monday reads: "The future of our land, water and climate are at risk . . . and so are the voices of Canadians."

"Silence is not an option."

Activists claim the Tories have declared "war on democracy and the environment" accusing the government of weakening the country's environmental safeguards.

"What we're seeing on the part of the federal government at the behest of the oil industry is just an unprecedented, crass smearing of the environmental movement…and an attempted evisceration of the most important environmental laws in this country through the federal budget," said Rick Smith, executive director of Environmental Defence, a group aligned with the Black Out campaign.

The government's claim that environmentalists are trying to obstruct industry and economic growth is "nonsense," Smith told CTV's Power Play on Monday.

"We're pragmatists," he said.

Under the new federal plan, the government would have 45 days to decide if an assessment is needed for major economic projects. Any review would take a maximum of two years.

Ottawa would also recognize provincial assessments if they meet federal standards, as well as cut the number of agencies responsible for reviews to three, down from about 40.

Oliver has said the new rules will prevent long delays in project approvals that threaten job-creation and hamper the economy.

The Canadian Association of Retired Persons also joined calls to break up the omnibus bill, saying changes to the Old Age Security program should be debated separately. The government is increasing the age of eligibility for OAS to 67 from 65.

"CARP members would be shattered to learn that such a fundamental part of our social safety net was rushed through Parliament on the strength of the government's parliamentary majority alone, without adequate opportunity for full debate," CARP's vice-president Susan Eng wrote in an open letter to MPs Monday.