WASHINGTON – Five oil giants. Five plans for coping with an oil spill, all written by the same tiny Texas subcontractor.

The government-mandated plans all came under attack at a congressional hearing Tuesday: Three of them listed the phone number for the same University of Miami marine science expert, Peter Lutz — who died in 2005. Four talked about the need to protect walruses, which, as Rep. Edward Markey, D-Mass., dryly noted, “have not called the Gulf of Mexico home for 3 million years.” The plans also mentioned protecting sea lions and seals, which aren’t found in the Gulf either.

The five oil companies submitted these plans — each more than 500 pages long and each relying on the same reassuring language — as part of their applications for permits to drill deepwater wells in the Gulf. The firms assured the government that they could handle oil spills much larger than the one now threatening the region’s environment and economy. And each time, the Minerals Management Service approved the plan and gave the go-ahead for drilling.

Yet House Energy and Commerce Chairman Henry Waxman, D-Calif., said that the “cookie-cutter” plans show that “none of the five oil companies has an adequate response plan” for a spill like the one that began April 20 with a blowout on a BP well.

“It could be said that BP is the one bad apple in the bunch,” Rep. Bart Stupak, D-Mich., said at a hearing of the House Energy and Environment subcommittee. “But unfortunately they appear to have plenty of company. Exxon and the other oil companies are just as unprepared to respond to a major oil spill in the Gulf as BP.”

The firms’ top executives offered a mixture of regret and defense. Exxon Mobil chief executive Rex Tillerson said provisions for walrus protection in Gulf plans are “an embarrassment.” Grilled by Stupak about how the companies could say they could handle spills many times the size of the current one, Tillerson also conceded, “We are not well-equipped to handle them.”

But he asserted that whenever large spills happen, “there will be impacts, as we are seeing.” And he added, “We’ve never represented anything different than that.” He said the company’s plans contain a worst-case scenario “that the MMS and the Coast Guard require us to calculate using their methodologies, and that’s why it’s in there.”

Tillerson said that prevention was the best strategy, and he and the executives from Conoco Phillips, Chevron and Shell Oil criticized BP’s handling of the well blowout, which killed 11 workers and sank the Deepwater Horizon rig. “We would not have drilled the well the way they did,” the Exxon chief said.

Lawmakers stressed the need to have plans in place in case all else failed. And whereas the companies have hired top-tier contractors to carry out their search for oil and gas, they relied on smaller, less well-known companies to handle spill plans.

The spill response plans for all five companies were written by the same firm, the Response Group. Although it has operations in at least seven cities, the Houston-based firm’s website says the company has about 35 employees. (One current assignment: calling 50,000 people who have visited BP offices and getting their e-mail addresses and contact information.)

Waxman also said the five companies rely on Marine Spill Response to provide equipment. “When you look at the details, it becomes evident these plans are just paper exercises,” he said.

The response plans, which the committee posted on its website, show that the companies also used common assumptions for different wells. BP used the same model for all its wells in the Gulf, using a location about 33 miles away from the where the accident occurred.

One of the few unique aspects was in Exxon Mobil’s plan. The company included 13 press release drafts “for almost any occasion,” Stupak said.

The gap between a worst-case oil spill and the promises the firms made about their ability to handle one is not limited to the Gulf. For example, in its exploration plans for Alaska, Shell analyzed the prospect of only a diesel fuel spill of 48 barrels (2,000 gallons), reasoning that a larger crude oil spill would be unlikely because the water is shallow. The MMS accepted this assumption.