Environmental groups today filed a lawsuit challenging tomorrow's oil and gas lease sale in the Gulf of Mexico, the nation's first since the Deepwater Horizon disaster.

The complaint in the U.S. District Court for the District of Columbia argues the Interior Department failed to fully gauge the impacts of the BP PLC oil spill and neglected to consider postponing the lease.

The lawsuit comes less than 24 hours before Interior's Bureau of Ocean Energy Management is set to auction 21 million acres of western Gulf waters for development. The agency today said it has received 241 bids from 20 companies, an indication of strong industry interest.

But the agency's supplemental review of the lease violated the National Environmental Policy Act and the Endangered Species Act, according to plaintiffs in the case, which include Oceana, Defenders of Wildlife, the Natural Resources Defense Council and the Center for Biological Diversity.

"The [environmental impact statement] admits the government doesn't have all the information on the impacts of Deepwater Horizon," said Catherine Wannamaker, senior attorney for the Southern Environmental Law Center, which is representing the groups. "They said that's not necessary to make a decision on the sale, and we disagree."

In addition, Interior's review improperly dismisses the chances of a catastrophic oil spill as a "low probability event," Wannamaker said.

Wannamaker said groups have also sent a 60-day notice in which they will argue that Interior violated the ESA by approving the sale. The groups have not filed an emergency request to halt the lease, she said.

Oil industry advocates said the lawsuit fails to acknowledge the comprehensive investigations and reforms Interior has adopted in the wake of the BP spill. Critics said the lawsuit has little chance of succeeding.

"There were a lot of significant lessons learned, and from those lessons learned there have been significant actions taken," said Erik Milito, the American Petroleum Institute's group director for upstream and industry operations.

Interior today said it attracted 241 bids from 20 companies on 191 tracts off the Texas coast. The results suggest bidding is roughly on par with the last sale in the western Gulf in August 2009, which garnered 189 bids from 27 companies on 162 tracts.

Milito said it was too early to tell how much companies were willing to pay for those lease but that early results appeared "robust."

"It's good news," he said. "We need to maintain this pipeline of lease sales."

Interior Secretary Ken Salazar will deliver brief remarks at the opening of tomorrow's 10 a.m. lease sale at the Mercedes-Benz Superdome in New Orleans.

Interior said lease blocks are located in federal waters up to 250 miles offshore, in water depths of up to 11,000 feet. The agency estimates the sale could result in production of up to 423 million barrels of oil.