It comes as thousands came together for what was billed as an 'emergency demonstration' in London 's Parliament Square today.

The undercover officers wore replicas of timepieces worth £110,000 to lure thieves in Mayfair, which has the highest rate of watch robberies in Europe.

One of the yobs, Yakob Harket, 21, can be seen snatching a replica Patek Philippe Rose Gold watch from the female officer's ...