A politician drowning in beer and scotch (5,3)
I believe the answer is:
stamp out
'scotch' is the definition.
(I've seen this before)
'a politician drowning in beer' is the wordplay.
'politician' becomes 'MP' (Member of Parliament).
'drowning in' is an insertion indicator.
'beer' becomes 'stout' (type of beer).
'a'+'mp'='amp'
'amp' put into 'stout' is 'STAMP OUT'.
'and' acts as a link.
(Other definitions for stamp out that I've seen before include "Suppress with heavy foot" , "Eradicate - as with heavy foot (5,3)" , "A stout MP (anag.)" , "Completely dispose of" , "Scotch" .)