According to the London Metropolitan Police force, on the day Prince William says,” I do”, there will be around 5000 police officers on duty to protect them and protect the day. The police force has already rejected requests from Islamic groups to protest outside Westminister Abbey on the event and Police are considering blocking their ability to protest at other sites in the area.
The police department has approximately 50K staff in total so 10% of the police force will be protecting Prince William on his big day – with an estimated £1.1 Million budget just for that single day which doesnt really consider that police are working already on securing the route that the Price will take to the Abbey.
With any luck the metropolitan police force will be putting more officers on active duty that day than just the 5000 that have been allocated to the wedding. If they do not then I can forsee a high risk of criminal activity taking advantage of the rather low presence of police through the rest of the London area.
By the way, if he proposed on a 3 month holiday to some exotic place, where does he go for the Honeymoon?
References
BBC News






