Agree with right-winger getting despatched (7)
I believe the answer is:
consent
'agree with' is the definition.
(thesaurus)
'right-winger getting despatched' is the wordplay.
'right winger' becomes 'con' (conservative).
'getting' means one lot of letters go next to another.
'despatched' becomes 'sent' (to despatch is to send off).
'con'+'sent'='CONSENT'
(Other definitions for consent that I've seen before include "authorisation" , "Agree or comply" , "Give approval" , "Agree(ment)" , "Say yes to something" .)