The prime minister is involved; so is the U.S. deputy secretary of State. The BBC is changing policies. But Bob Vylan remains steadfast.

This story originally appeared in Los Angeles Times. The BBC issued a formal apology after broadcasting a controversial performance from the rap-punk group Bob Vylan at England's Glastonbury festival.

"We deeply regret that such offensive and deplorable behaviour appeared on the BBC," the broadcaster said in a new statement