Part 1: Espionage, sabotage and persons acting for foreign powers Powers of search etc. Schedule 6: Arrest without warrant
Section 27 and Schedule 6 provide a power of arrest and provisions about subsequent detention. These provisions are modelled on those at section 41 and Schedule 8 of the Terrorism Act 2000. Section 27(1) provides that a constable may arrest without a warrant anyone who they reasonably suspect is involved in foreign power threat activity. Section 33 defines involvement in foreign power threat activity, covering commission, preparation or instigation of certain acts or threats, which are specified offences under the Act (section 33(3)(a)) as well as acts or threats where the foreign power condition is met (see section 31) and the acts (a) involve serious violence against another person, (b) endanger the life of another person, or (c) create a serious risk to the health or safety of the public or a section of the public. In addition, involvement in foreign power threat activity includes conduct which facilitates or gives support or assistance to those involved in commission, preparation, or instigation of such acts of threat (section 33(1)(b) and (c).
	Subsection (3) provides that a person must be released not later than 48 hours after arrest. If the person was already detained under another power, the 48 hours is taken from the time they were detained under that other power. The other powers of detention are listed in subsection (4) as section 24 of the Police and Criminal Evidence Act 1984, Article 26 of the Police and Criminal Evidence (Northern Ireland) Order 1989, section 41 of and Schedule 7 to the Terrorism Act 2000, section 1 of the Criminal Justice (Scotland) Act 2016, and Part 1 of Schedule 3 to the Counter-Terrorism and Border Security Act 2019.
	Part 5 of schedule 6 covers the requirement for reviews of detention to be carried out. Section 27 (5) provides that a person arrested must be released if, following such a review, the review officer does not authorise continued detention. The provision does not apply if the person is detained awaiting an application or decision on further detention, as set out in subsections (6) and (7).
	Paragraphs 37 and 44 of Schedule 6 provide that a judicial authority can issue a warrant of further detention and may extend or further extend a person’s detention. Section 27 (6) and (7) make clear that a person may be detained pending the making of an application for such a warrant or whilst awaiting the outcome of the proceedings on an application.
	Where a warrant of further detention or extension or further extension has been granted, section 27 subsection (8) indicates that the person may be detained for the period of time specified in the warrant. This is subject to the conditions on detention in paragraph 45 of Schedule 6 which provide that a person must be released if the matters on which the judicial authority authorised further detention no longer apply.Subsection (9) provides that where an application to extend detention is refused, a person can continue to be detained in accordance with this section (i.e., for up to 48 hours).
	Subsections (10) and (11) provides that if a person is removed to hospital for medical treatment, any time during which the person is being questioned in hospital or on the way there or back for the purpose of obtaining relevant evidence is to be included in detention time calculations. Any other time is not to be included. "Relevant evidence" is defined in subsection (12) as evidence which indicates that the detained person is, or has been, involved in foreign power threat activity.
	Subsection (13) provides that any person who has the powers of a constable in one part of the United Kingdom can exercise their power of arrest under subsection (1) in any part of the United Kingdom.