Obscure English Tories upset with Commons at first (8)
I believe the answer is:
esoteric
'obscure' is the definition.
(thesaurus)
'english tories upset with commons at first' is the wordplay.
'english' becomes 'e' (abbreviation).
'upset with' indicates an anagram.
'at first' indicates taking the first letters.
The first letter of 'commons' is 'c'.
'tories' anagrammed with 'c' can make 'soteric'.
'e'+'soteric'='ESOTERIC'
(Other definitions for esoteric that I've seen before include "Hard to understand" , "Mystic" , "Intended for the few" , "of rarefied tastes" , "Tie score (anagram)" .)