Politician attending debauched event with fellow countryman (10)
I believe the answer is:
compatriot
'fellow countryman' is the definition.
(I've seen this in another clue)
'politician attending debauched event' is the wordplay.
I cannot really understand how this works, but
'politician' could be 'mp' (Member of Parliament) and 'mp' is found in the answer.
'attending' could be 'at' (e.g. at school means attending school) and 'at' is found within the answer.
This explanation may well be incorrect...
'with' is the link.
Can you help me to learn more?
(Another definition for compatriot that I've seen is " Fellow citizen".)