Spooner's announcement to close Justice Centre is finished early (3,5)
I believe the answer is:
cut short
'justice centre is finished early' is the definition.
I can't judge whether this definition defines the answer.
'spooner's announcement to close' is the wordplay.
'spooner's announcement' becomes 'cut' (I can't justify this - if you can you should give a lot more credence to this answer).
'to close' becomes 'short' (similar in meaning).
'cut'+'short'='CUT SHORT'
Can you help me to learn more?
(Other definitions for cut short that I've seen before include "Abridge" , "instruction to army barber" , "Interrupted" , "Truncate" , "ended prematurely" .)