Jacinda Ardern, New Zealand’s new prime minister, has brought Labour back to power after nearly a decade in the wilderness. She became party leader only seven weeks before last month’s general election, and instantly transformed the party’s prospects – only to have the lead she quickly established beaten back in the final days of the campaign by a brutal National party attack on her tax policies. In the end, Labour won 37% of the vote, National 44%, but it was Ms Ardern rather than the National leader Bill English who managed to construct a governing coalition that stretches from the populist New Zealand First party to the Greens, who, for the promise of a climate change commission and more money for the environment, are committed to a confidence-and-supply arrangement – supporting Labour budgets and backing it on confidence motions. Now she has been sworn in, the country’s youngest prime minister in 150 years and its third female leader since 1997.

Labour campaigned to reduce child poverty, build more affordable homes, make university free and every river swimmable: so far, so Labour. But she also committed to slow the rate of immigration from 50,000 to 30,000 a year and ensure that employers looked for New Zealand workers before they brought in migrants – even though employment rates are high, and unemployment low and forecast to stay that way. Her first move in power was equally populist: she announced plans to ban foreigners from buying existing homes: New Zealand real estate has become a priority item on the global super-rich’s shopping list, not only for buyers from China and the rest of Asia but for Americans looking for investments secure from the consequences of a Trump presidency – what the New Yorker called Doomsday prep. The discovery that the PayPal founder and Trump supporter Peter Thiel had been given New Zealand citizenship and then bought a £4.5m property on the ultra-desirable Lake Wanaka provoked a media storm, but although Auckland house prices have rocketed to an average price of over NZ$1m, it is not obvious that banning foreign buyers will do much to free up housing for New Zealanders at the affordable end of the market.

Gestures to popular opinion may be necessary. But, as the new prime minister acknowledges, this is a country where, for all its tourist allure and its green potential, one in three children is growing up in a poverty that disproportionately affects Maori and Pasifika families. Earlier this month, Unicef described the country’s levels of inequality and deprivation as “deeply concerning”. Ms Ardern, who has announced that she will be the first minister for child poverty reduction, promises to make it a priority, introducing a payment to assist families raising young children, increasing rent support and extending paid parental leave from 18 to 26 weeks.

The new prime minister may be only 37, but she has served a long political apprenticeship, working for both the former New Zealand Labour prime minister Helen Clark, and then for Tony Blair. Yet despite the kind of background that is now often disparaged, she has managed to combine a degree of pragmatism (under pressure, she backed off from her tax proposals) with a vote-winning authenticity. Holding it all together will require all her skills.