Neither the left nor the right think David Cunliffe is a viable leader for the Labour Party, going forward.

Right-wing commentator Matthew Hooton said Cunliffe, who today said he would resign from the role, was leading the Labour party down the path of destruction.

"He seems to be determined to be as destructive as he can to the Labour Party."

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If Cunliffe won the race for leader it could be the end of the party as it had been known since 1916, Hooton said.

The party would "tear itself apart" during the leadership campaign and if Cunliffe won, the party would cease to be legitimate in the public mind.

The best outcome for Labour would have been for Grant Robertson to go in unopposed and take the leadership, with Jacinda Ardern as his deputy.

A "new, young, future-looking" line-up in the Labour Party would have the best chance against National's ageing front bench in the 2017 election, he said.

If Robertson did win it was questionable as to whether Cunliffe would be loyal to the new leader as he promised to be, Hooten said, adding that he was not loyal to former leaders Phil Goff or David Shearer.

"He has chosen the most destructive path possible."

Hooten said the Labour party's system for electing a leader was a "farce".

The majority of Labour party members did not vote in last year's leadership election, according to figures given to Fairfax Media.

A leader selected through a system where the majority of members did not vote was not a viable leader, he said.

Meanwhile, this was great news for National, which was sitting back, watching the labour storm and taking its time to put together its new cabinet.

"David Cunliffe is doing everything he can to help John Key get his fourth term."

Former Labour Party president Mike Williams said Cunliffe had done the right thing by resigning.

"I don't believe you can produce the worst result in 90 years and not walk the plank."

However, Cunliffe would not be seen as a legitimate leader if he was re-elected, Williams said.

Cunliffe should, and possibly would, withdraw his nomination to contest the leadership, he said.

But under a new leader the party did have the potential to come back and take out the 2017 election.

Williams echoed Hooton's thoughts, that National would be celebrating Labour's latest debacle.

Former Labour Party general secretary Mike Smith said the future of the Labour Party did not rest entirely in the hands of the leader.

The most important thing was to carry out a proper review of the party's election performance and deal with the deeper issues within Labour, Smith said.

"To me it's not just about the jockey, if the horse is not fit then the jockey doesn't matter."

Smith said Cunliffe was not his choice for leader last year when the party was in a similar situation but would not say who his pick for leader was this time round.

"I'm much more interested in getting the party's organisation and strategy and approach to the electorate right."

Smith said he would have preferred a "more measured process", with the party taking time to undertake a full review before jumping into another leadership election, but Cunliffe had made his decision.