Show minister Uxbridge, where there's a vacancy (5)
I believe the answer is:
revue
'show' is the definition.
(revue is a kind of show)
'minister uxbridge where there's a vacancy' is the wordplay.
'minister' becomes 'rev' (I've seen this before).
'where there's a vacancy' means to remove the middle letters (the word is emptied out or made vacant).
'uxbridge' with its middle removed is 'ue'.
'rev'+'ue'='REVUE'
(Other definitions for revue that I've seen before include "Musical show" , "Entertainment consisting of sketches" , "Stage entertainment with sketches, songs and dance" , "Stage show" , "Theatrical show" .)