Maintained tidiness needs sorting out (8)
I believe the answer is:
insisted
'maintained' is the definition.
(I've seen this before)
'tidiness needs sorting out' is the wordplay.
'needs sorting out' indicates anagramming the letters (I've seen this in other clues).
'tidiness' is an anagram of 'INSISTED'.
(Other definitions for insisted that I've seen before include "Declared emphatically about tidiness" , "Demanded firmly" , "Maintained firmly" , "Declared or demanded emphatically" , "... repeated" .)