It's after the deadline for both sides in labour dispute (4)
I believe the answer is:
late
'it's after the deadline for both sides in labour dispute' is the definition.
I can't tell whether this definition defines the answer.
'it's after the deadline for both sides in labour' is the wordplay.
'it's after' means one lot of letters go next to another.
'the deadline for' becomes 'la' (I can't justify this - if you can you should believe this answer much more).
'both sides in' says to hollow out the word (remove centre letters) (only the side letters remain).
'labour' becomes 'trouble' (trouble is a kind of labour).
'trouble' with its centre taken out is 'te'.
'la'+'te' is 'LATE'.
Can you help me to learn more?
(Other definitions for late that I've seen before include "Behind schedule" , "Far into the night" , "Departed - behind time" , "Behindhand" , "Former, delayed" .)