A Conservative minister is right (8)
I believe the answer is:
accurate
'is right' is the definition.
('accurate' can be similar in meaning to 'right')
'a conservative minister' is the wordplay.
'conservative' becomes 'c' (abbreviation commonly used in UK politics).
'minister' becomes 'curate' ('curate' can be a synonym of 'minister').
'a'+'c'+'curate'='ACCURATE'
(Other definitions for accurate that I've seen before include "carefully and precisely" , "not deviating from the truth?" , "Spot on" , "Correct, right" , "Factual" .)