Cockney had choice for pet-rescue (8)
I believe the answer is:
adoption
'pet-rescue' is the definition.
I can't tell whether this definition defines the answer.
'cockney had choice' is the wordplay.
'cockney had' becomes ''ad' ('had' said with a cockney accent, dropping the 'H').
'choice' becomes 'option' (synonyms).
'ad'+'option'='ADOPTION'
'for' is the link.
Can you help me to learn more?
(Other definitions for adoption that I've seen before include "Choosing (of a candidate for office)" , "Legal process of taking a child into one's family" , "process to select candidate" , "Appropriation from another source" , "Espousal, a fostering" .)