A BTP constable does not lose the ability to exercise his powers when off duty. Section 22 of the Infrastructure Act 2015 repealed section 100(3)(a) of the Anti-terrorism, Crime and Security Act 2001 which required BTP officers to be in uniform or in possession of documentary evidence (i.e. their warrant card) in order to exercise their powers. The repeal of this subsection, which came into effect on 12 April 2015, now means BTP officers are able to use their powers on or off duty and in uniform or plain clothes regardless of whether they are in possession of their warrant card.