The High Court may, on an application under this subsection, by order annul a Convention adoption or a Convention adoption order on the ground that the adoption or order is contrary to public policy.
The High Court may, upon an application under this subsection—
(a) order that an overseas adoption or a determination shall cease to be valid in Great Britain on the ground that the adoption or determination is contrary to public policy or that the authority which purported to authorise the adoption or make the determination was not competent to entertain the case;
(b) decide the extent, if any, to which a determination has been affected by a subsequent determination.
Any court in Great Britain may, in any proceedings in that court, decide that an overseas adoption or a determination shall, for the purposes of those proceedings, be treated as invalid in Great Britain on either of the grounds mentioned in subsection (2).
An order or decision of the Court of Session on an application under subsection (3) of section 6 of the Adoption Act 1968 shall be recognised and have effect as if it were an order or decision of the High Court on an application under subsection (3) of this section.
Except as provided by this section ... the validity ofa Convention adoption, a Convention adoption order, an overseas adoption or a determination shall not be impugned in England and Wales in proceedings in any court.