Go back on green plan, to a point (6)
I believe the answer is:
renege
'go back on' is the definition.
(synonyms)
'green plan to a point' is the wordplay.
'plan' indicates anagramming the letters (plan can mean organise).
'to a point' becomes 'e' (compass point).
'green' is an anagram of 'reneg'.
'reneg'+'e'='RENEGE'
(Other definitions for renege that I've seen before include "Go back on an obligation" , "In card games, revoke" , "Change one's mind" , "Don't follow suit when you can" , "Default" .)