Minister starts to embarrass Rishi Sunak with a large U-turn? (8)
I believe the answer is:
reversal
'u-turn?' is the definition.
(u-turn is a kind of reversal)
'minister starts to embarrass rishi sunak with a large' is the wordplay.
'minister' becomes 'rev' (short for reverend).
'starts to' says to take the initial letters.
'with' means one lot of letters go next to another.
'large' becomes 'L' (eg in clothes sizes).
The initial letters of 'embarrass rishi sunak' is 'ers'.
'rev'+'ers'+'a'+'l'='REVERSAL'
(Other definitions for reversal that I've seen before include "that doesn't affect mum or dad" , "misfortune!" , "A turning backwards" , "switch" , "Change of fortune" .)