Upper-class rogue helps -- Tory seat might need this (10)
I believe the answer is:
upholstery
'seat might need this' is the definition.
(a seat might be upholstered)
'upper-class rogue helps tory' is the wordplay.
'upper-class' becomes 'u' (similar in meaning).
'rogue' indicates anagramming the letters (letters go rogue).
'helps'+'tory'='helpstory'
'helpstory' anagrammed gives 'pholstery'.
'u'+'pholstery'='UPHOLSTERY'
(Other definitions for upholstery that I've seen before include "Padding and covering of furniture" , "Craft of covering furniture" , "Chair springs and covers" , "Work done on furniture" .)