Updated

A coalition of conservation groups sued the federal government Tuesday over its approval of oil spill response plans for an Arctic Ocean drilling program.

The lawsuit does not seek to block Shell Oil from beginning to drill this summer as planned, and an attorney for Oceana, one of the groups suing, said it's unlikely the case will be resolved in a timeframe that could affect drilling this year.

However, the case could prevent drilling in future seasons, if the coalition succeeds in getting the approvals set aside, attorney Michael LeVine said.

The lawsuit alleges the Bureau of Safety and Environmental Enforcement and U.S. Interior Department officials violated environmental law, the Clean Water Act and the Endangered Species Act in approving spill plans for the Beaufort and Chukchi seas.

In a statement ahead of the lawsuit's filing, the groups said the Bureau of Safety and Environmental Enforcement "rubber-stamped" oil spill response plans "that rely on unbelievable assumptions, include equipment that has never been tested in Arctic conditions, and ignore the very real possibility that a spill could continue through the winter."

A Shell Alaska spokesman, Curtis Smith, said the company remains confident that the process the federal government followed in approving its spill plans was thorough "and will easily withstand legal review." An Interior Department spokesman declined to comment.

Shell is not named as a party in the case. Groups in the coalition include the Alaska Wilderness League, Center for Biological Diversity, Greenpeace Inc., National Audubon Society, Natural Resources Defense Council, Ocean Conservancy, Oceana, Pacific Environment, Resisting Environmental Destruction on Indigenous Lands and the Sierra Club.

LeVine said the coalition's work has been geared toward protecting the Arctic Ocean, not stopping Shell, and it wants to make sure the government upholds the law when approving oil spill response plans because more drilling proposals are expected.

Heavier-than-normal sea ice looks to push the expected start of drilling from mid-July to the first week of August, Smith said. Shell also is working with the U.S. Coast Guard to determine the proper classification for its oil spill containment barge. Smith said he expects that issue to be resolved soon, and said it shouldn't further delay drilling plans.