Starmer bans me getting involved; shame (13)
I believe the answer is:
embarrassment
'shame' is the definition.
(embarrassment is a kind of shame)
'starmer bans me getting involved' is the wordplay.
'getting involved' indicates anagramming the letters (involved can mean confusing or complex).
'starmer'+'bans'+'me'='starmerbansme'
'starmerbansme' anagrammed gives 'EMBARRASSMENT'.
(Other definitions for embarrassment that I've seen before include "Surplus" , "Self-consciousness, shame" , "Sheepishness" , "Mortification" , "it accounts for red faces" .)