Repulsive former English LibDem leader crushing resistance (9)
I believe the answer is:
execrable
'repulsive' is the definition.
(thesaurus)
'former english libdem leader crushing resistance' is the wordplay.
'former' becomes 'ex'.
'english' becomes 'e' (abbreviation).
'libdem leader' becomes 'cable' (former Liberal Democrat leader Vince Cable).
'crushing' means one lot of letters goes inside another.
'resistance' becomes 'r' (abbreviation).
'cable' going around 'r' is 'crable'.
'ex'+'e'+'crable'='EXECRABLE'
(Other definitions for execrable that I've seen before include "Abominable, detestable" , "Hated" , "Awful" , "Appallingly bad" , "Accursed" .)