Law Enforcement (Powers and Responsibilities) Act 2002

An authorisation for the exercise in a public place of the special powers conferred by this Division may be given in accordance with this Division if the police officer giving the authorisation—

has reasonable grounds for believing that there is a large-scale public disorder occurring or a threat of such a disorder occurring in the near future, and

is satisfied that the exercise of those powers is reasonably necessary to prevent or control the public disorder.

In giving an authorisation, the police officer is to be satisfied that the nature and extent of the powers to be conferred by the authorisation are appropriate to the public disorder that is occurring or threatened.