Split from leader of Champagne socialists (5)
I believe the answer is:
cleft
'split' is the definition.
(I've seen this before)
'leader of champagne socialists' is the wordplay.
'leader of' suggests taking the first letters.
'socialists' becomes 'left'.
The initial letter of 'champagne' is 'c'.
'c'+'left'='CLEFT'
'from' is the link.
(Other definitions for cleft that I've seen before include "Split in the palate" , "division" , "Fissure; divided" , "rent" , "split along natural lines" .)