Irritating Tories upset Middle East leaders … (8)
I believe the answer is:
tiresome
'irritating' is the definition.
(I've seen this before)
'tories upset middle east leaders' is the wordplay.
'upset' is an anagram indicator.
'leaders' says to take the initial letters.
The first letters of 'middle east' is 'me'.
'tories' with letters rearranged gives 'tireso'.
'tireso'+'me'='TIRESOME'
(Other definitions for tiresome that I've seen before include "Fatiguing; boring" , "Draggy - unamusing" , "Tedious, dull" , "Annoying, being a nuisance" , "Aggravating" .)