Election 2020: Helen Clark on what Labour's victory has in common with the Great Depression

Former Prime Minister Helen Clark is drawing parallels with the post-Great Depression election in 1938 and Jacinda Ardern's landslide victory in the middle of the Covid-19 pandemic.

"It's a 1938-style result, when Labour was rewarded for the climb out of the Great Depression," Clark told the Herald.

Labour won 55.8 per cent of the party vote in 1938. Last night they won 49.1 per cent - enough for a parliamentary majority, given the amount of wasted votes.

"For this one, you had a pandemic the likes of which hasn't been seen since [the flu pandemic in] 1918 and the existential threat to everybody's health," Clark said.

"A Government that handled that by global standards as well as anyone could was going to be rewarded for that - and that's what's happened."

Clark, who is co-chairing a review of the World Health Organisation's Covid-19 response, said the Covid-positive port worker announced today was a reminder of how highly infectious the disease is.

"But the key thing is to stamp on it. That's really quite comforting."

She said she had messaged Ardern to congratulate her on the "fantastic result", but added that Labour winning a parliamentary majority was "not that surprising" in the Covid-19 context.

"MMP is almost designed so that you never get an absolute majority, but these are extraordinary times.

"The important thing is Jacinda has struck a tone of wanting to carry on being inclusive, and that's the way you build long-term relationships for when the results aren't quite so overwhelming."

For that reason, Clark encouraged Ardern to have a governing arrangement with the Greens - which Ardern has not ruled out.

"It was a very safe campaign and the reality is that elections in New Zealand are won in the centre. This election has seen a lot of normally National supporters give their party vote to Labour.

"I think she'll want to continue to govern in a way that's inclusive of quite a broad spectrum, and with respect to where the economy can go from here, [she] definitely would want to include the voices of those in the business community about how to rebuild.

She said the Greens should be careful about seeking a coalition arrangement with Labour, echoing a similar sentiment from Sir Michael Cullen.

"Minor parties tend to get squeezed in coalitions because the major party tends to get the credit for everything.

"I think the Greens have played their hands quite well and ministers outside the Cabinet, and they might want to reflect on whether that is the best strategy for them going forward. It enables them to keep a distance while also having influence."

Clark said NZ First leader Winston Peters had had "a long run".

"We've seen Winston come and go and come and go before. A lot hangs on what he wants now. Does he decide the fishing up north is good?

"For the record, it's important to say that Jacinda would not have had a chance to be PM had Winston not decided to support that. There will always be appreciation from the Labour Party for that."