A group of dangerous people operating on behalf of the British government who would be disavowed by the same government if ever caught, which would be highly unlikely. Who would want to confront such people?
Do unto others before they do it to you. Three former Special Forces soldiers empty the courts and fill the morgues when they target the criminal world's untouchables. A former military policeman soon realises that he has well armed and highly trained vigilantes operating in the capital.