When Marama Davidson, ahead of an official trip to New Zealand’s Hawkes Bay, found out that low-income families living in motels there would be evicted to make way for visiting dignitaries like her, she refused to be part of it.

After Davidson – co-leader of the left-leaning Green party that is part of New Zealand’s power-sharing government led by Jacinda Ardern’s Labour – saw the headlines, she cancelled the booking and packed a tent in her suitcase instead.

“They were kicking people out of motels that were being used for emergency housing,” she says. “I was like, ‘Oh my God, I hate that we’ve got people living in motels, but I don’t want to be the reason for them to live in the car for a week.’”

Davidson had an even better time at the campground during the trip to visit the Māori performing arts festival Te Matatini, she says. The young performers and their families were staying there too; she fixed her hair and makeup for official events in the communal bathroom block alongside them and “was stealing all their babies” while groups rehearsed.

“Camping is my deal,” Davidson, 46, says. So are the arts; her father is the actor Rawiri Paratene and her mother an activist; she was raised at the heart of a kind of Māori cultural renaissance – political, linguistic, creative – with some of New Zealand’s most towering Indigenous writers, artists and agitators as her doting babysitters. Leadership was natural; parliamentary politics was not.

When the Guardian visited her office in the capital, Wellington, in February – before parliament closed for the national lockdown intended to eliminate Covid-19 from New Zealand – Davidson was barefoot and dispensing hugs to anyone who arrived.

There is tension between her idealism and her pragmatism in the story about sleeping in a tent while on official business. “I understand that we need to solve the systemic issue and me camping for two nights does not solve the systemic issue,” she says. “I got all that.”

It is also reflective of the Greens’ uneasy relationship with power: the party of activists and environmentalists returned its best electoral results while in opposition against the previous centre-right government, and the current electoral term is the first time the party – with its eight parliamentarians – has been part of the ruling group.

But the trade-off for the discomfort, Davidson says, are policies such as the one she was shortly to announce: a plan to reduce the housing agency’s reliance on motel rooms for emergency accommodation for the homeless, and to build more short-term housing for those on New Zealand’s longest-ever public housing waiting list, at a cost of $300m.

“Essentially, we are operating in a system which goes against our values,” she says of the Green party. Parliament is “a little, insulated bubble of disconnection,” inhabited by a “hostile” politics.

“But if I wasn’t here, if we weren’t here, people would be missing out on the difference that we are making,” she adds. That will be the pitch for the Green party at September’s election, Davidson says: telling stories about what its lawmakers did when they touched the levers of power.

Marama Davidson talks to Jacinda Ardern during debate over the zero carbon bill last year. Photograph: Hagen Hopkins/Getty Images

She mentions bolstered protections for victims of domestic abuse, safeguards for water and the environment, collective Māori approaches to Indigenous matters. Her party has to prove it’s not just “similar to Labour” in order to survive.

That was in February; by April, New Zealand had been shut down in the government’s efforts to combat the coronavirus and Davidson’s parliamentary world had collided, hard, with her refuge at home where time “on the couch with my babies” is prized.

The household “bubble” in self-isolation at her South Auckland home numbers eight people: Davidson, her husband of more than 20 years, her eldest daughter and three youngest children, her son-in-law and her baby granddaughter. Two other adult children live nearby. Davidson is working “14 to 16 hour” days in politics, representing the Green party on a parliamentary committee set up to scrutinise the government’s response to the virus. She seeks refuge from the chaos in the garage, or with her laptop balanced atop a stack of books on two bar stools in the bedroom.

“On the one hand I’ve been able to put my children to bed every night and that has been an absolute luxury for me,” she says, adding that in order to spend time with her family in the evenings, she is often still working at 2am.

Politics is emphatically not “for life” for Davidson, but her husband and children agreed that the chance to lead a political party was worth the sacrifice.

Do the work. Get it done

“I think what helps us all get through as a family is going, ‘Holy crap, what an opportunity this is for me, for them, for us,’” she says.

Davidson has helmed the party jointly with Shaw since 2018, after the spectacular downfall of her friend, the former co-leader Metiria Turei – the woman who “showed me that it was possible to be in this space and still operate as authentically as I can,” Davidson says.

Turei resigned her post after a media furore when she volunteered that she had claimed larger benefits than she was entitled to as a young mother on social welfare. Her point about the difficulties of survival on welfare in New Zealand was drowned out by rancour over her wrongdoing, but Davidson says Turei’s “bravery” had “changed the narrative” about poverty in New Zealand.

Journalists who ask her about welfare payment increases these days, she says, are on the side of the beneficiaries. But when Davidson learned the woman who mentored her into politics was stepping aside less than two months before the 2017 election , she had “a very raw moment of grief and feeling quite bewildered as to whether I could carry on”.

“The way I reconciled it was: ‘Do the work. Get it done,’” she recalls. She cried in her car outside a campaign event. Less than a year later, she was the party’s co-leader.

Before Turei had urged her into politics, Davidson worked at New Zealand’s human rights commission for a decade. Her penchant for activism, combined with an absence of ministerial portfolios allows Davidson more flexibility to petition the government than she might otherwise have.

Her best-known stand came as an opposition MP when she was thrown out of parliament for objecting to the then-prime minister John Key’s accusation that his opponents supported “rapists.” She stood in the debating chamber and referred to her own sexual assault; the demand that she leave prompted a walk-out in support from other lawmakers, many of whom said they had been assaulted too.

She spoke further about the abuse, which had happened when she was a young child, on a news podcast in 2018. It generated a huge outpouring – talkback callers, messages, headlines – of support and recognition.

“You don’t know how it’s going to affect you until you see it in broad daylight out in the world,” Davidson says, of sharing the story. “And then I saw I saw it all around the place and then I was like, ‘What have I done? What have I done?’ And I felt raw and overexposed.”

Her activism had always been personal, but this was “one of the most deeply personal things,” she says, because she had carried not anger, but shame, about the incidents.

“This is mine. And now everyone else has got it,” she thought at the time. It prompted a scary, but ultimately cathartic, phone call with her father, who had not known the details of the episodes.

“I was like… ‘Forget it’s out there. It’s out there. I’ve got my dad. I’ve got my whole family,” Davidson says. “I am invincible. I’m done. We’re good.”

In the remote parliamentary committee hearings she participates in while the Covid-19 lockdown rolls on, Davidson often asks the captains of industry and government ministers about the plight of low-wage workers after the crisis ends.

But she does not believe, as some of her parliamentary colleagues do, that the country will have to choose between jobs and wellbeing.

“I do have to continue to both reject that narrative and put up the new, the better story.”