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

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

After punk duo Bob Vylan chanted "death to the IDF" live on air, the BBC has vowed to take action to "ensure proper accountability" for those found to be responsible for the broadcast.