The expert suggested that the King is given an “extra element of power” when he is with his wife.

Speaking on behalf of Betfair Bingo, he added: “We would previously see him tuck his hand into his jacket or play with his cufflinks. However, we don’t see any of that now, which tells me that his inner power of confidence has evolved.

“With Camilla by his side, he is given an extra element of power. She is clearly his rock and forcefield during public events.”

Stanton went on to add: “All of the smiles at yesterday’s reception were very genuine, both from Charles and Camilla.

“This was displayed by the crows’ feet at the side of their faces.

“The gestures that they flashed weren’t default settings, which is when someone is trying to look happy when you’re not.”