Drunk, I complain constantly about Tory leader's party (8)
I believe the answer is:
litigant
'party' is the definition.
(I know that litigant is a type of party)
'drunk i complain constantly' is the wordplay.
'drunk' becomes 'lit' (slang term).
'complain constantly' becomes 'gant' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'lit'+'i'+'gant'='LITIGANT'
'about tory leader's' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for litigant that I've seen before include "Plaintiff" , "One going to law" , "Party in lawsuit" , "Instigator of a courtly battle" , "One conducting a law suit" .)