BP and Anadarko Petroleum have been exposed to billions of dollars in potential fines after the judge who will oversee the Deepwater Horizon court case ruled they were liable for civil damages under federal pollution laws.
Carl Barbier’s decision means the US government can pursue operator BP and partner Anadarko for civil penalties at the trial, due to begin on Monday.
Mr Barbier also said rig contractor Transocean might be liable for some cleanup costs from the Macondo blowout in April 2010.
Anadarko has already agreed to pay BP £2.5billion to settle claims between the companies over the spill. In return, BP agreed to indemnify it for most spill-related costs. BP is still in a legal battle with Transocean for its alleged part in the fatal accident.