Parliamentary and Diplomatic Protection

Parliamentary and Diplomatic Protection (PaDP) is a branch of the Protection Command within the Specialist Operations directorate of London's Metropolitan Police Service. == Duties == A unit of the Metropolitan Police Service, PaDP is responsible for providing officers (armed and unarmed) to protect the Palace of Westminster, which contains the Houses of Parliament; it protects government ministers and provides advice on threat levels.

Source: Wikipedia — Parliamentary and Diplomatic Protection (CC BY-SA 4.0)