(1)Subsection (2) applies where it is not reasonably practicable for an authorising officer to consider an application for an authorisation under section 93 and—
(a)if the authorising officer is within paragraph (b) or (e) of section 93(5), it is also not reasonably practicable for the application to be considered by any of the other persons within the paragraph concerned; or
(b)if the authorising officer is within paragraph (a), (c), (d), (f) or (g) of section 93(5), it is also not reasonably practicable for the application to be considered by his designated deputy.
(2)Where this subsection applies, the powers conferred on the authorising officer by section 93 may, in an urgent case, be exercised—
(a)where the authorising officer is within paragraph (a) or (d) of subsection (5) of that section, by a person holding the rank of assistant chief constable in his force;
(b)where the authorising officer is within paragraph (b) of that subsection, by a person holding the rank of commander in the metropolitan police force;
(c)where the authorising officer is within paragraph (c) of that subsection, by a person holding the rank of commander in the City of London police force;
(d)where the authorising officer is within paragraph (e) of that subsection, by a person holding the rank of assistant chief constable in the Royal Ulster Constabulary;
(e)where the authorising officer is within paragraph (f) or (g) of that subsection by a person designated for the purposes of this section by the Director General of the National Criminal Intelligence Service or, as the case may be, of the National Crime Squad;
(f)where the authorising officer is within paragraph (h) of that subsection, by a customs officer designated by the Commissioners of Customs and Excise for the purposes of this section.
(3)A police member of the National Criminal Intelligence Service or the National Crime Squad appointed under section 9(1)(b) or 55(1)(b) may not be designated under subsection (2)(e) unless—
(a)he has held the rank of assistant chief constable in a police force maintained under section 2 of the [1996 c. 16.] Police Act 1996 or under or by virtue of section 1 of the [1967 c. 77.] Police (Scotland) Act 1967, or in the Royal Ulster Constabulary, or
(b)he has held the rank of commander in the metropolitan police force or the City of London police force.
(4)In subsection (1), “designated deputy”—
(a)in the case of an authorising officer within paragraph (a) or (d) of section 93(5), means the person holding the rank of assistant chief constable designated to act in his absence under section 12(4) of the [1996 c. 16.] Police Act 1996 or, as the case may be, section 5(4) of the [1967 c. 77.] Police (Scotland) Act 1967;
(b)in the case of an authorising officer within paragraph (c) of section 93(5), means the person authorised to act in his absence under section 25 of the [1839 c. xciv.] City of London Police Act 1839; and
(c)in the case of an authorising officer within paragraph (f) or (g) of section 93(5), means the person designated to act in his absence under section 8 or 54.