Poor Republican put inside summoned to court (4,2)
I believe the answer is:
hard up
'poor' is the definition.
(similar in meaning)
'republican put inside summoned to court' is the wordplay.
'republican' becomes 'r' (abbreviation).
'put inside' is an insertion indicator.
'summoned to court' becomes 'hadup' (I can't explain this - if you can you should believe this answer much more).
'r' going within 'hadup' is 'HARD-UP'.
Can you help me to learn more?
(Other definitions for hard up that I've seen before include "Being without cash" , "Panto Baron; needy" , "It's not easy to be in straitened circumstances" , "Impoverished" , "Impecunious" .)