Colleague following blundering Tory leader Sunak mostly an easy target (4,5)
I believe the answer is:
aunt sally
'easy target' is the definition.
(I've seen this before)
'colleague following blundering tory leader sunak mostly' is the wordplay.
'colleague' becomes 'ally' (ally can mean a colleague or associate).
'following' means one lot of letters go next to another.
'blundering' indicates an anagram (I've seen 'blunders' mean this).
'leader' says to take the initial letters.
'mostly' means to remove the last letter (most but not all of the word).
The first letter of 'tory' is 't'.
'sunak' with its final letter taken away is 'suna'.
't'+'suna'='tsuna'
'tsuna' with letters rearranged gives 'aunts'.
'ally' after 'aunts' is 'AUNT SALLY'.
'an' acts as a link.
(Other definitions for aunt sally that I've seen before include "easy to criticise" , "Lusty Lana as target of criticism or missiles" , "Shy" , "Family member" , "Fair target" .)