Politician covered in sauce rises suddenly (5)
I believe the answer is:
jumps
'rises suddenly' is the definition.
(jump can mean to rise up suddenly)
'politician covered in sauce' is the wordplay.
'politician' becomes 'MP' (Member of Parliament).
'covered in' indicates putting letters inside.
'sauce' becomes 'jus' (French term for a gravy sauce).
'mp' inserted inside 'jus' is 'JUMPS'.
(Other definitions for jumps that I've seen before include "obstacles for equestrians" , "Starts" , "Leaps" .)