Conservative to go briefly to north-east for break (10)
I believe the answer is:
contravene
'for break' is the definition.
(contravening is a kind of breaking)
'conservative to go briefly to north-east' is the wordplay.
'conservative' becomes 'con' (abbreviation for Conservative).
'to go' becomes 'travel' (synonyms).
'briefly' means to remove the last letter.
'to north east' becomes 'ne'.
'travel' with its last letter removed is 'trave'.
'con'+'trave'+'ne'='CONTRAVENE'
(Other definitions for contravene that I've seen before include "Offend against (law)" , "Break" , "To dispute the proposition" , "Go against (rules)" , "Conflict with" .)