Unforeseen, spin backfiring for minister (10)
I believe the answer is:
chancellor
'minister' is the definition.
(thesaurus)
'unforeseen spin backfiring' is the wordplay.
'unforeseen' becomes 'chance' (I can't explain this - if you can you should believe this answer much more).
'spin' becomes 'roll'.
'backfiring' says the letters should be written in reverse.
'roll' back-to-front is 'llor'.
'chance'+'llor'='CHANCELLOR'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for chancellor that I've seen before include "Imposer of taxes" , "See 8" , "Head of government" , "11 17 down [CABINET MINISTER]" , "Government leader" .)