Tories sincere? Explain! (8)
I believe the answer is:
construe
'explain' is the definition.
(I've seen this in another clue)
'tories sincere?' is the wordplay.
'tories' becomes 'cons' (short for Conservatives).
'sincere?' becomes 'true' ('true' can be a synonym of 'sincere').
'cons'+'true'='CONSTRUE'
(Other definitions for construe that I've seen before include "Counters (anag) - interpret" , "Counters so as to interpret or explain" , "Read - trounces (anag)" , "Understand" , "Interpret in a particular way" .)