Kirkland & Ellis and Arnold & Porter are set to defend BP against the 26,000 claims the petrochemical giant says have been filed so far as a result of the oil leak in the Gulf of Mexico.

BP confirmed the appointment of the two US law firms as defence counsel, with Kirkland's team including partners Andrew Langan, Richard Godfrey and Matthew Regan. BP's defence team also reportedly includes Houston practice Andrews Kurth.

Market estimates of the total cost of damages BP could face as a result of the leak range between $5.2bn (£3.5bn) and $12.5bn (£8.6bn). Under US law, the cap on each claim for economic damages sits at $75m (£51.7m). However, BP has said it will disregard this limit and pay any claims it deems legitimate.

Of the claims made to date, BP has already made 11,650 payments worth a combined $930m (£640.25m).

The spill, which was the result of an oil well blow out under the sea on 20 April, has been compared to the Exxon Valdez oil spill that occurred in Prince William Sound, Alaska, on 24 March 1989. The Alaskan spill resulted in a payout of more than $4.3bn (£2.96bn) in damages across two decades.

Martyn Day, senior partner of claimant firm Leigh Day & Co, said: "I imagine the bulk of claims will be resolved over the next year and then there will be a residue of cases that may linger on for the next decade. BP will be bending over backwards to be seen to be acting fast and avoid the protracted process that was experienced by Exxon."

Hausfeld chairman Michael Hausfeld added: "The fallout for BP will depend on how responsive they are to claims made over the coming months."