Part 2: Lawful interception of communications Chapter 1: Interception and examination with a warrant Section 36: Further provision about modifications
A modification which adds a name or description to a warrant, or which adds a factor to a warrant, can only be made if the modification is necessary and the conduct authorised by the modification is proportionate to what is sought to be achieved. This means that adding something to a warrant is subject to the same necessity and proportionality test as issuing a warrant. This section also sets out that the additional protections for Members of Parliament, etc. (section 26), items subject to legal privilege (section 27), items containing confidential journalistic material (section 28) and communications that identify a journalist’s source (section 29) apply in relation to a decision to make a major modification of a warrant as apply in relation to a decision to issue a warrant.
	Subsection (5) makes clear that a modification which relates to the communications of a Member of Parliament or member of another relevant legislature can only be made by a Secretary of State (or a member of the Scottish Government for warrants issued by the Scottish Minister) and only has effect after the decision to make the modification has been approved by the Judicial Commissioner. Subsection (6) provides that a major modification in relation to items subject to legal privilege, items which contain confidential journalistic material, and communications which identify a journalist’s source can only be made by a Secretary of State or a member of the Scottish Government, or in urgent case, a senior official acting on their behalf. Such modifications must be approved by a Judicial Commissioner before they have effect, except where the person making the modification considers that there is an urgent case to make it. Subsections (8) and (9) provide for circumstances where the Secretary of State has taken a decision to modify a warrant but it is not reasonably practicable for them to sign the instrument. The rules in subsections (8) and (9) are the same as for issuing warrants.