Unruly argument in open discussion meetings with Liberal left (4-3-3)
I believe the answer is:
free-for-all
'unruly argument' is the definition.
'open discussion meetings with liberal left' is the wordplay.
'open' becomes 'free' (similar in meaning).
'discussion meetings' becomes 'fora' (plural of 'forum').
'with' means one lot of letters go next to another.
'liberal' becomes 'l' (abbreviation).
'left' becomes 'l' (common abbreviation).
'free'+'fora'+'l'+'l'='FREE-FOR-ALL'
'in' acts as a link.
(Other definitions for free-for-all that I've seen before include "Disorganised event" , "Public brawl" .)