Freedom to cancel a berth unexpectedly (5,7)
I believe the answer is:
carte blanche
'freedom' is the definition.
(I've seen this before)
'cancel a berth unexpectedly' is the wordplay.
'unexpectedly' indicates an anagram.
'cancel'+'a'+'berth'='cancelaberth'
'cancelaberth' is an anagram of 'CARTE-BLANCHE'.
'to' is the link.
(Other definitions for carte blanche that I've seen before include "Unrestricted authority" , "Complete authority" , "Free hand" , "Full discretionary power" , "Complete discretion" .)