Part 2: Prevention and Investigation Measures Five-year limit on imposition of measures Section 42: Five-year limit for Part 2 notices
This section makes provision for when a Part 2 notice comes into force, how long it will remain in force and for how long it can be extended. Subsection (1)(b) specifies that a Part 2 notice remains in force for a year, and subsection (1)(a) that the year begins from the date on which it is served or from a later date which may be specified in the notice. The purpose of subsection (1)(a) is to ensure that the one-year period does not begin before the measures imposed by the notice have effect on the individual. An example might be a case in which a Part 2 notice is prepared in contingency, or for other reasons in advance of its service, or in which it is served in advance of the time when it is intended to come into force. An example of when a Part 2 notice might be prepared (and permission sought) on a contingency basis is where a law enforcement agency speaks to someone engaged in foreign power threat activity to inform them that they are being directed by a foreign power and to understand whether they were aware of this. In a situation where the person refuses to engage with the law enforcement agency or acknowledge the information provided, it may be necessary to rely on a Part 2 notice and serve a notice right away.
	Subsections (2) and (3) provide that the Secretary of State may, after a Part 2 notice has been in force for a year, extend it for a further year (but may only do so up to a maximum of four times). The notice may only be extended if the Secretary of State continues to: reasonably believe that the individual is or has been involved in foreign power threat activity (condition A); and reasonably considers both that it is necessary to impose measures on the individual (condition C) and that it is necessary to impose the measures specified in the Part 2 notice (condition D).
	Subsection (4) provides that the operation of the five-year time limit is subject, in particular, to the exceptions and provisions in sections 49 and 50 relating to revocation and revival of a Part 2 notice and to replacement of a Part 2 notice. As noted above, this section also interacts with condition B in section 40.