Miner and former Conservative mostly drinking wine (9)
I believe the answer is:
excavator
'miner' is the definition.
(thesaurus)
'former conservative mostly drinking wine' is the wordplay.
'former' becomes 'ex'.
'conservative' becomes 'tory' (informal term for a Conservative Party member).
'mostly' means to remove the last letter.
'drinking' is an insertion indicator.
'wine' becomes 'cava' (type of Spanish wine).
'ex'+'tory'='extory'
'extory' with its final letter taken off is 'extor'.
'extor' placed around 'cava' is 'EXCAVATOR'.
'and' acts as a link.
(Another definition for excavator that I've seen is " Powered machine for digging earth".)