The previous time that the US and UK overthrew Iran's government (https://en.wikipedia.org/wiki/1953_Iranian_coup_d'%C3%A9tat), they used the BBC in that way.

  Roosevelt told the Shah that he was in Iran on behalf of the American and British secret services, and that this would be confirmed by a code word the Shah would be able to hear on the BBC the next night. Churchill had arranged that the BBC would end its broadcast day by saying not 'it is now midnight' as usual, but 'it is now exactly midnight'