Dismay -- poor Tories cannot win without Women's Institute (13)
I believe the answer is:
consternation
'dismay' is the definition.
(thesaurus)
'poor tories cannot win without women's institute' is the wordplay.
'poor' indicates an anagram.
'without' indicates named letters should be taken away.
'women's institute' becomes 'wi'.
'tories'+'cannot'+'win'='toriescannotwin'
'toriescannotwin' with 'wi' removed is 'toriescannotn'.
'toriescannotn' anagrammed gives 'CONSTERNATION'.
(Other definitions for consternation that I've seen before include "Anxiety, dismay" , "Alarm" , "Feelings of dismay" , "Worry" , "Dismay - cast-iron tenon (anag)" .)