Royal Experts believe he would have had appropriate security during the Westminster Abbey ceremony on March 29 and throughout his stay in Windsor.

The event is expected to be attended by the Duke’s friends, colleagues, and representatives of organisations he sponsored.

Angela Levin, Harry’s biographer, said: “He has snubbed the Duke of Edinburgh but really he is snubbing the Queen.”

She went on: “He has got this all wrong. If he comes over for a royal event he gets police protection. What they won’t do is, if he goes out with his friends he gets security.

“He’ll probably use this same excuse to try to get out of the Platinum Jubilee celebrations.“