Go before disrupting leadership of Anthony Eden etc. (8)
I believe the answer is:
antecede
'go before' is the definition.
(I've seen this before)
'disrupting leadership of anthony eden etc' is the wordplay.
'disrupting' indicates an anagram.
'leadership of' says to take the initial letters (the letters which lead the words).
The first letter of 'anthony' is 'a'.
'a'+'eden'+'etc'='aedenetc'
'aedenetc' is an anagram of 'ANTECEDE'.
(Other definitions for antecede that I've seen before include "go before, in rank" , "Lead" .)