One restructured NHS attendance, becoming more influential (2,3,9)
I believe the answer is:
in the ascendant
'more influential' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'one restructured nhs attendance' is the wordplay.
'one' becomes 'i' (Roman numeral).
'restructured' indicates anagramming the letters (I've seen 'restructuring' mean this).
'nhs'+'attendance'='nhsattendance'
'nhsattendance' is an anagram of 'ntheascendant'.
'i'+'ntheascendant'='IN THE ASCENDANT'
'becoming' is the link.
Can you help me to learn more?
(Other definitions for in the ascendant that I've seen before include "becoming more influential - with 23a" , "on the way up" .)