Allude to the right to free movement (5)
I believe the answer is:
refer
'allude' is the definition.
(I've seen this before)
'the right to free movement' is the wordplay.
'the right' becomes 'r' (abbreviation).
'to' says to put letters next to each other.
'movement' indicates an anagram (letters move around).
'free' anagrammed gives 'efer'.
'r'+'efer'='REFER'
'to' is the link.
(Other definitions for refer that I've seen before include "Make allusion, direct attention with words" , "Fail (an exam candidate)" , "Make an allusion, or send on" , "Advert, cite" , "Direct elsewhere" .)