Politician returned to seat next to queen (11)
I believe the answer is:
backbencher
'politician' is the definition.
(backbencher is a kind of politician)
'returned to seat next to queen' is the wordplay.
'returned' becomes 'back' (I've seen this before).
'to seat' becomes 'bench' (bench is a kind of seat**).
'next to' is a charade indicator (letters next to each other).
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'back'+'bench'+'er'='BACKBENCHER'
(Other definitions for backbencher that I've seen before include "MP not holding office" , "Rank and file MP" , "MP without office" , "Legislator" , "Representative" .)