Conservative changed roles to become more intimate (6)
I believe the answer is:
closer
'more intimate' is the definition.
('close' can be similar in meaning to 'intimate')
'conservative changed roles' is the wordplay.
'conservative' becomes 'c' (abbreviation commonly used in UK politics**).
'changed' indicates an anagram.
'roles' is an anagram of 'loser'.
'c'+'loser'='CLOSER'
'to become' is the link.
(Other definitions for closer that I've seen before include "Cresol (anag.)" , "more reticent" , "More near or imminent" , "one concludes" , "Nearer or meaner" .)