in this section,"the 1981 Act" means the British Nationality Act 1981.
In section 40 of the 1981 Act (deprivation of citizenship), after subsection (5) (which requires notice to be given to a person to be deprived of citizenship) insert "(5A): Subsection (5) does not apply if it appears to the Secretary of State that --
(a) the Secretary of State does not have the information needed to be able to give notice under that subsection,
(b) it would for any other reason not be reasonably practicable to give notice under that subsection, or
(c) notice under that subsection should not be given --
(i) in the interests of national security,
(ii) in the interests of the relationship between the United Kingdom and another country, or
(iii) otherwise in the public interest."