United Kingdom of Great Britain and Northern Ireland

(1) If, on an application for naturalisation as a British citizen made by a person of full age and capacity, the Secretary of State is satisfied that the applicant fulfils the requirements of Schedule 1 for naturalisation as such a citizen under this subsection, he may, if he thinks fit, grant to him a certificate of naturalisation as such a citizen.
(2) If, on an application for naturalisation as a British citizen made by a person of full age and capacity who on the date of the application is married to a British citizen, or is the civil partner of a British citizen the Secretary of State is satisfied that the applicant fulfils the requirements of Schedule 1 for naturalisation as such a citizen under this subsection, he may, if he thinks fit, grant to him a certificate of naturalisation as such a citizen. (British Nationality Act 1981, Sec. 6)⁴

(1) In this section a reference to a person’s “ citizenship status ” is a reference to his status as—
(a) a British citizen,
(b) a British overseas territories citizen,
(c) a British Overseas citizen,
(d) a British National (Overseas),
(e) a British protected person, or
(f) a British subject.
(2)The Secretary of State may by order deprive a person of a citizenship status if the Secretary of State is satisfied that deprivation is conducive to the public good.
...
(4) The Secretary of State may not make an order under subsection (2) if he is satisfied that the order would make a person stateless.
(4A) But that does not prevent the Secretary of State from making an order under subsection (2) to deprive a person of a citizenship status if—
(a) the citizenship status results from the person's naturalisation,
(b) the Secretary of State is satisfied that the deprivation is conducive to the public good because the person, while having that citizenship status, has conducted him or herself in a manner which is seriously prejudicial to the vital interests of the United Kingdom, any of the Islands, or any British overseas territory, and
(c) the Secretary of State has reasonable grounds for believing that the person is able, under the law of a country or territory outside the United Kingdom, to become a national of such a country or territory.
... (British Nationality Act 1981, Sec. 40)⁵

(1) A court or tribunal determining a question which has arisen in connection with a Convention right must take into account any—
(a) judgment, decision, declaration or advisory opinion of the European Court of Human Rights,
(b)opinion of the Commission given in a report adopted under Article 31 of the Convention,
(c)decision of the Commission in connection with Article 26 or 27(2) of the Convention, or
(d)decision of the Committee of Ministers taken under Article 46 of the Convention,whenever made or given, so far as, in the opinion of the court or tribunal, it is relevant to the proceedings in which that question has arisen.
(2) Evidence of any judgment, decision, declaration or opinion of which account may have to be taken under this section is to be given in proceedings before any court or tribunal in such manner as may be provided by rules.
... (Human Rights Act 1998, Sec. 2)

(1) Subsection (2) applies in any proceedings in which a court determines whether a provision of primary legislation is compatible with a Convention right.
(2) If the court is satisfied that the provision is incompatible with a Convention right, it may make a declaration of that incompatibility.
(3) Subsection (4) applies in any proceedings in which a court determines whether a provision of subordinate legislation, made in the exercise of a power conferred by primary legislation, is compatible with a Convention right.
(4) If the court is satisfied—
(a) that the provision is incompatible with a Convention right, and
(b) that (disregarding any possibility of revocation) the primary legislation concerned prevents removal of the incompatibility,it may make a declaration of that incompatibility.
(5) In this section “court” means—
(a) the Supreme Court;
(b) the Judicial Committee of the Privy Council;
(c) the Court Martial Appeal Court;
(d) in Scotland, the High Court of Justiciary sitting otherwise than as a trial court or the Court of Session;
(e) in England and Wales or Northern Ireland, the High Court or the Court of Appeal.
(f) the Court of Protection, in any matter being dealt with by the President of the Family Division, the Chancellor of the High Court] or a puisne judge of the High Court.
... (Human Rights Act 1998, Sec. 4)⁶