Moderate papers holding centre ground finally close (9)
I believe the answer is:
intercede
'moderate' is the definition.
(thesaurus)
'papers holding centre ground finally close' is the wordplay.
'papers' becomes 'id' (identification papers).
'holding' indicates putting letters inside.
'ground' is an anagram indicator (grind the letters ).
'finally' says to take the final letters.
The final letter of 'close' is 'e'.
'centre' with letters rearranged gives 'nterce'.
'id' placed around 'nterce' is 'interced'.
'interced'+'e'='INTERCEDE'
(Other definitions for intercede that I've seen before include "Come between as mediator" , "Mediate" , "Act as peacemaker between two parties" , "step in" , "Plead in favour of" .)