(1) An adopting parent who has been on adoptive leave under section 42 or additional adoptive leave under section 43 shall cause his or her employer (or, where he or she is aware of a change of ownership of the undertaking concerned, the successor) to be notified in writing of his or her intention to return to work and of the date on which he or she expects to return to work -
(a) at the same time that he or she causes his or her employer to be notified of his or her intention to take leave under either of those sections, or
(b) not later than 4 weeks before the date on which he or she expects to return to work,
whichever is the later.
(2) Subsections (2) and (3) of section 20 shall apply to an adopting parent taking leave under sections 42 and 43 and the references in those subsections to subsection (1) shall be construed as including a reference to subsection (1) of this section.