Senior Labour MP David Cunliffe faces certain demotion after failing to rule out challenging leader David Shearer at the weekend.
Sources close to 3 News have confirmed Shearer has more than 22 votes out of the 34 in the caucus which means he is safe as leader.
Cunliffe can only muster around 12 at most - he needs 14 to push this to a party wide vote - which would include members and unions.
Cunliffe entertained the idea of a challenge at the weekend party conference - which completely overshadowed Shearer's strong performance and speech and undermined the conference.
The repeated refusal from Cunliffe to rule out the leadership question when confronted by 3 News political reporter Patrick Gower over the weekend sent shockwaves through the conference.
Only this morning has Cunliffe appeared to have officially backed off a challenge - clearly realising he does not have the numbers.
But Labour Party sources say Shearer will punish Cunliffe by calling a caucus this week or next at the latest and will kick him off the front bench as economic development spokesman.
At the same caucus, Shearer will seek an endorsement as leader which 3 News now understands he will win.
It's understood a number of senior MPs are furious at Cunliffe's antics over the weekend.
An MP who didn't want to be named but is clearly in Camp Shearer said Cunliffe will be demoted to the backbenches and will spend years there.
“His political career has reached its pinnacle, he has committed treachery against our leaders over 4 years, even if he spends years in the wilderness he will only ever get back to the mid-benches. He is a fink that ruined the conference," says the MP.
Suggestions that Cunliffe will be expelled are understood to be far-fetched and incorrect.
It meant Labour's massive promise to build 100,000 affordable homes - and labelled a 'bribe' by National - was lost in the headlights of the leadership debacle.