Mrs Churchill and Mr Attlee in England's capital (10)
I believe the answer is:
clementine
'capital' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'mrs churchill and mr attlee in england's' is the wordplay.
I cannot really see how this works, but
'mrs' could be 'clementi' and 'clementi' is found within the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
'england' could be 'e' (short for England) and 'e' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for clementine that I've seen before include "suits citrus production" , "Citrus fruit" , "Forty-niner's daughter; Mrs W. S. Churchill" , "juicy type" , "my darling girl?" .)