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' means one lot of letters goes inside another.
'politician' becomes 'MP' (Member of Parliament).
'ale' placed around 'mp' is 'AMPLE'.
'to have' is the link.
(Other definitions for ample that I've seen before include "Large, accommodating" , "Adequate" , "Plentiful; large" , "Bulky" , "Buxom" .)