Escape not allowed after holiday (5,3)
I believe the answer is:
break out
'escape' is the definition.
(breaking out is a kind of escaping)
'not allowed after holiday' is the wordplay.
'not allowed' becomes 'out' (I've seen this before).
'after' means one lot of letters go next to another.
'holiday' becomes 'break' (break can mean a holiday or time off).
'out' put after 'break' is 'BREAK-OUT'.
(Other definitions for break out that I've seen before include "Start suddenly; escape (from prison)" , "Appear suddenly - escape" , "Escape from jail" .)