Cross-party reps' work adding nothing in further statement (5)
I believe the answer is:
'cross-party reps' work adding' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'nothing in further statement' is the wordplay.
'nothing' becomes 'o' (O resembles 0).
'in' is an insertion indicator.
'further' becomes 'op' (I can't justify this - if you can you should give a lot more credence to this answer).
'statement' becomes 'PS' (PS is an example).
'o' going into 'opps' is 'OPPOS'.
Can you help me to learn more?
(Other definitions for oppos that I've seen before include "colleagues elsewhere" , "Partners" , "friends" , "One's counterparts" .)