The degree of division was also obvious from the failure of a marathon seven-hour caucus meeting to reach any agreement on how to resolve the party's leadership crisis.
Cunliffe's hold on the leadership was already under question after last Saturday's dreadful result. But he has since boxed himself into a corner. He has made strategic mistakes, notably his ill-judged speech conceding defeat in which he said he would take only his "share" of the blame.
And he is now entangled in Labour's complex and seemingly inflexible rules for choosing or removing a leader.
Under these, Labour's leader must win a caucus re-endorsement motion within three months of an election. If he or she fails to get at least 60 per cent of the vote plus one MP, the matter goes to a party-wide ballot of MPs, party members and union affiliates.
Cunliffe wants such a party-wide vote to reinforce his authority as leader. But losing the caucus re-endorsement vote would destroy his credibility with the voting public.
But he could resign as leader and then throw his hat back into the ring and seek to win the party-wide ballot - something he would probably succeed in doing.
But he would be seen as trying to save his neck and thwarting the caucus. And he is refusing to resign.
Labour's worst defeat in 92 years is justification enough for his removal as leader.
It is time for senior and respected figures in the party to step in and call a halt to the madness.
Debate on this article is now closed.