Left in charge over European committee appointment (10)
I believe the answer is:
rapporteur
'committee appointment' is the definition.
The definition suggests a singular noun which matches the answer.
'left in charge over european' is the wordplay.
'left' becomes 'port' (left side of a ship - opposite of starboard).
'in' indicates putting letters inside.
'charge over' becomes 'rap' (both can mean blame or responsibility. I am not sure about the 'over' bit.).
'european' becomes 'Eur' (abbreviation for European).
'rap'+'eur'='rapeur'
'port' put inside 'rapeur' is 'RAPPORTEUR'.
Can you help me to learn more?
(Other definitions for rapporteur that I've seen before include "Record-keeper" , "researcher" , "One investigating" , "Recorder" .)