You have a right to 52 weeks’ adoption leave if you have worked for the same employer for at least 26 weeks by the week in which you are notified of being matched with a child for adoption. A couple adopting jointly can choose who takes adoption leave and who takes paternity leave.
The Paternity & Adoption Leave Regs 2002 , regs 15-27

Statutory adoption pay – To qualify for ‘statutory adoption pay’ (SAP), you must have worked for the same employer for at least 26 weeks by the end of the week in which you are notified of being matched with a child for adoption and have average gross weekly earnings of at least £129. SAP can be paid for up to 39 weeks. It is paid at 90% of your average weekly earnings (with no upper limit) for the first six weeks. The remaining 33 weeks are paid at the standard rate of £194.32 a week, or 90% of your average earnings (whichever is less). You can continue to be paid SAP if you work for your employer for up to 10 days during y