Improving the chook batter could threaten the status quo (4,3,4)
I believe the answer is:
rock the boat
'threaten the status quo' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'improving the chook batter' is the wordplay.
'improving' is an anagram indicator (letters must be sorted out or rectified).
'chook'+'batter'='chookbatter'
'chookbatter' is an anagram of 'ROCK THE BOAT'.
'could' is the link.
Can you help me to learn more?
(Other definitions for rock the boat that I've seen before include "make trouble" , "Disturb settled position" , "Upset status quo" , "one way to get to bathe" , "It is sung" .)