One parliamentarian nincompoop... I have to be emotionless (9)
I believe the answer is:
impassive
'be emotionless' is the definition.
(similar in meaning)
'one parliamentarian nincompoop i have' is the wordplay.
'one' becomes 'I' (Roman numeral).
'parliamentarian' becomes 'MP' (Member of Parliament).
'nincompoop' becomes 'ass' (I've seen this in another clue).
'i have' becomes 'I've' (contraction of 'I have').
'i'+'mp'+'ass'+'ive'='IMPASSIVE'
'to' acts as a link.
(Other definitions for impassive that I've seen before include "Unconcerned" , "Unflappable" , "Inscrutable, not showing emotion" , "unfeeling" , "Phlegmatic" .)