Never working, good-for-nothing (2,2,7)
I believe the answer is:
on no account
'never' is the definition.
(thesaurus)
'working good-for-nothing' is the wordplay.
'working' becomes 'on'.
'good-for-nothing' becomes 'noaccount' ('no-account' can be a synonym of 'good-for-nothing').
'on'+'noaccount'='ON NO ACCOUNT'
(Other definitions for on no account that I've seen before include "Never" , "Certainly not!" , "Where immediate payments are recorded?" .)