A dozen environmental groups have told a US federal court they are renewing a challenge to the leasing in 2008 of areas off Alaska’s north-west shore, where Royal Dutch Shell hopes to drill exploratory wells this summer.

The groups have twice obtained court rulings that said environmental analysis preceding the Chukchi sea sale was flawed. The Department of the Interior in March concluded it had corrected mistakes.

Erik Grafe, an attorney for Earthjustice, said on Monday the environmental groups disagreed and would lay out their claims in a future court filing.

In 2008, leases were sold on 11,168 square kilometres (4,312 square miles), bringing in $2.7bn for the federal government. Shell spent $2.1bn on high bids and began exploratory drilling in 2012. It has since spent more than $7bn, including the cost of staging drilling vessels and a support fleet in Seattle for the 2015 open water season.

Conservation and Alaska native groups said in their lawsuit the former Minerals Management Service had based the sale’s environmental review on projected extraction of only 1bn barrels of oil. A court-ordered supplemental review assumed an extraction of 4.3bn barrels.

The environmental groups indicated in the filiing on Monday that they would continue their claim that the environmental review for the lease sale was insufficient, Grafe said.

The groups remain concerned about the effects of drilling around Hanna shoal, an underwater plateau 130km (80 miles) off the coast that is important walrus habitat, Grafe said.

The revised environmental analysis also failed to assess the climate effect of burning 4.3bn barrels of oil, he said.

“This is an energy decision,” he said. “It’s about where we’re going to get our energy in the future. That needs to be made in the context of climate policy and that wasn’t done here.”

John Callahan, a spokesman for the interior department’s Bureau of Ocean Energy Management, said the agency could not comment on the litigation.

Environmental groups strongly oppose Arctic outer continental drilling and say industrial activity and a major spill would harm marine mammals already hurt by climate warming.