A sheet of soft paper under discussion (2,5)
I believe the answer is:
at issue
'under discussion' is the definition.
(at issue means currently being discussed)
'a sheet of soft paper' is the wordplay.
I cannot really see how this works, but
'a' is found in the answer.
'paper' could be 'tissue' (tissue paper is a kind of paper) and 'tissue' is found within the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for at issue that I've seen before include "Questionable" , "in dispute" , "Being discussed or disputed" , "under debate" , "In question, under discussion" .)