Note a Guardian columnist, one boiling up inside? (9)
I believe the answer is:
teakettle
'one boiling up inside?' is the definition.
'note a guardian columnist' is the wordplay.
'note' becomes 'te'.
'guardian columnist' becomes 'kettle' (Guardian columnist Martin Kettle).
'te'+'a'+'kettle'='TEAKETTLE'
(Other definitions for teakettle that I've seen before include "Vessel for boiling water" , "Kitchen item" , "Kitchen appliance" , "Boiler" .)