Official in trouble breaking strike (7)
I believe the answer is:
bailiff
'official' is the definition.
(I know that bailiff is a type of official)
'trouble breaking strike' is the wordplay.
'trouble' becomes 'ail' (synonyms).
'breaking' means one lot of letters goes inside another.
'strike' becomes 'biff' (I've seen this before).
'ail' going inside 'biff' is 'BAILIFF'.
'in' acts as a link.
(Other definitions for bailiff that I've seen before include "Sheriff's officer - landlord's agent" , "Landowner's agent" , "Law officer who helps sheriff, say to foreclose" , "Court official" , "Officer of court" .)