Labour leader fighting Tory seat in Bury (3,2,4)
I believe the answer is:
lay to rest
'bury' is the definition.
(synonyms)
'labour leader fighting tory seat' is the wordplay.
'labour leader' becomes 'l' (the leading letter of 'labour').
'fighting' is an anagram indicator.
'tory'+'seat'='toryseat'
'toryseat' anagrammed gives 'aytorest'.
'l'+'aytorest'='LAY TO REST'
'in' is the link.
(Other definitions for lay to rest that I've seen before include "Bury" , "Inter" , "Maybe put in shroud" , "Finally solve" .)