(1)Subject to subsection (2), section 40 does not apply—
(a)for the purposes of determining the forbidden degrees of consanguinity and affinity in respect of the law relating to marriage or to the eligibility of persons to register as civil partners of each other, or
(b)in respect of the crime of incest.
(2)On the making of an adoption order, the adopter and the person adopted are deemed, for all time coming, to be within the forbidden degrees in respect of the law relating to marriage, to such eligibility and to incest.
(3)Section 40 does not apply for the purposes of any provision of—
(a)the British Nationality Act 1981 (c. 61),
(b)the Immigration Act 1971 (c. 77),
(c)any instrument having effect under either of those Acts, or
(d)any other law for the time being in force which determines British citizenship, British overseas territories citizenship or British Overseas Citizenship.