No good reason to accept Tory leader as a politician (7)
I believe the answer is:
senator
'a politician' is the definition.
(I know that senator is a type of legislator)
'no good reason to accept tory leader' is the wordplay.
'no good' indicates an anagram (no good can mean faulty or defective).
'to accept' is an insertion indicator.
'leader' suggests taking the first letters.
The initial letter of 'tory' is 't'.
'reason' anagrammed gives 'senaor'.
'senaor' placed around 't' is 'SENATOR'.
'as' acts as a link.
(Other definitions for senator that I've seen before include "Clinton, perhaps" , "Statesman -- treason (anag)" , "Member of upper US assembly" , "Treason committed by member of Upper House" , "Upper house US Congressman" .)