Enough to have beer with politician (5)
I believe the answer is:
ample
'enough' is the definition.
(ample means enough or plenty)
'beer with politician' is the wordplay.
'beer' becomes 'ale' (type of beer).
'with' indicates putting letters inside.
'politician' becomes 'MP' (Member of Parliament).
'ale' going around 'mp' is 'AMPLE'.
'to have' acts as a link.
(Other definitions for ample that I've seen before include "Large, accommodating" , "Adequate" , "Plentiful; large" , "Bulky" , "Buxom" .)