Call into question tax introduced by Tory (7)
I believe the answer is:
contest
'call into question' is the definition.
(I've seen this in another clue)
'tax introduced by tory' is the wordplay.
'tax' becomes 'test' (taxing can mean testing or demanding).
'introduced by' says to put letters next to each other.
'tory' becomes 'con' (abbreviation for Conservative).
'test' put after 'con' is 'CONTEST'.
(Other definitions for contest that I've seen before include "Tournament" , "Competition or conflict" , "Competition; dispute" , "Oppose - competition" , "Match" .)