Labour leader David Shearer has left the door open for former economic development spokesperson David Cunliffe to rejoin the party's front bench - when he proves he can be trusted.
Mr Cunliffe was demoted to the back benches on Tuesday after failing to quell speculation he would challenge for the leadership.
Mr Shearer said the New Lynn MP has been undermining his leadership and he no longer trusts him.
He said he will miss Mr Cunliffe in his economic role, but until he proves he can be trusted there is no place for him on the front bench.
Labour MPs voted unanimously to endorse Mr Shearer on Tuesday after he called a special caucus meeting to end speculation about his leadership.
Only Mr Shearer spoke after the meeting, as the caucus agreed no one else should comment.
However, Mr Cunliffe posted a Facebook message of thanks to his supporters.
The Green Party says it would not be good for Labour, politics nor the public if speculation about Mr Shearer's leadership drags on.
Co-leader Metiria Turei told Morning Report her party has worked well with both Mr Cunliffe and Mr Shearer and the sooner the leadership issues are resolved the better.