WASHINGTON, May 2 (Reuters) - The U.S. government will keep a “boot on the neck” of BP Plc, as it responds to a huge oil spill in the Gulf of Mexico that threatens to become an economic and ecological catastrophe, Interior Secretary Ken Salazar said on Sunday.

“Our job basically is to keep the boot on the neck of British Petroleum to carry out the responsibilities they have both under the law and contractually to move forward and stop this spill,” Salazar told CNN’s “State of the Union” program.

He said there was “no doubt” that a mechanism that prevents oil from blowing out of the BP well was defective, adding that 100,000 barrels or more of oil could leak per day in a worst case scenario.