Vote in the French, welcomed by European court (5)
I believe the answer is:
elect
'vote in' is the definition.
(I've seen this before)
'the french welcomed by european court' is the wordplay.
'the french' becomes 'le' ('the' in French).
'welcomed by' means one lot of letters goes inside another (letters welcomed inside).
'european' becomes 'E' (abbreviation e.g. EU).
'court' becomes 'ct' (abbreviation used in road names).
'e'+'ct'='ect'
'le' put inside 'ect' is 'ELECT'.
(Other definitions for elect that I've seen before include "Vote into office" , "Preferred" , "Bring to office" , "Return" , "Appoint through ballot" .)