A historic environmental protection bill is in danger after a massive oil spill put a new focus on the perils of offshore drilling, a feature that was supposed to win wider support for the legislation.

The bill, supported by President Barack Obama, calls for new offshore drilling _ a concession by environmentalists. But with the tragedy off the Gulf Coast growing daily, even conservationists who have waited a decade for the legislation are now saying it will fail if offshore drilling remains in the bill.

"When you're trying to resurrect a climate bill that's face-down in the mud and you want to bring it back to life and get it breathing again, I don't think you can have offshore drilling against the backdrop of what's transpiring in the Louisiana wetlands," said Richard Charter, energy adviser to Defenders of Wildlife. "I think it's flat-lined."

Some Democrats, including two of New Jersey's congressmen and both of its senators, threatened Friday to pull their support if offshore drilling is included in the bill designed to curb emissions of pollution-causing gases blamed for global warming.

Introduction of the legislation was postponed on Monday for an unrelated reason. The bill aims to cut emissions of carbon dioxide and other greenhouse gases 17 percent below 2005 levels by 2020, and it also would expand domestic production of oil, natural gas and nuclear power.

Obama called for new offshore drilling in the Atlantic Ocean from Delaware to central Florida, and the northern waters of Alaska. He also asked Congress to lift a drilling ban in the oil-rich eastern Gulf of Mexico, 125 miles from Florida beaches.

The images of last week's explosion and the growing, uncontrolled spill in the Gulf of Mexico made the bill's road to approval much more difficult. The accident, which threatens wildlife and fishing grounds along the Gulf Coast, will likely force many wavering lawmakers to reconsider whether they support expanded drilling.

"I think that's dead on arrival," U.S. Sen. Bill Nelson, a Democrat from Florida, told CNN on Friday.

But South Carolina Sen. Lindsey Graham said Friday he has not wavered in his support. "We've had problems with car design, but you don't stop driving," he told The Greenville News. "The Challenger accident was heart-breaking but we went back to space."

A White House spokesman said this week that President Barack Obama remains committed, at least for now, to plans to expand drilling to new areas of the Outer Continental Shelf.

But David Jenkins, a spokesman for Republicans for Environmental Protection, said the politics of offshore drilling are "changing by the minute" as the spreading slick of oil threatens coastal states that traditionally support drilling.

"If this plays out, how many politicians will be jumping up and saying they won't vote for this because it doesn't include offshore drilling?" Jenkins said.

While the environmental community never embraced drilling, some muted or at least downplayed their opposition to Obama's proposal for the sake of the larger climate bill, said Steve Cochran, with the Environmental Defense Fund.

While the spill essentially kills any proposal for more drilling, he said it also demonstrates more than ever the need for a comprehensive energy bill that protects the environment.

"We need to take advantage of the opportunity of this bill to make sure we never face this situation again," he said.

Carl Pope, chairman of the Sierra Club, agreed. He said the authors of the bill will have to come up with a new formula to attract support from moderate Democrats, independents and Republicans.

"The oil industry spent 40 years building a story line that it knew what it was doing underwater and because it knew what it was doing we could allow it to turn our most sensitive coastline into oilfields," he said. "We've now been reminded once again that oil and water do not mix."