Jacinda Ardern, New Zealand’s outgoing prime minister, said leading the country was “the greatest privilege of my life” in her last public appearance before she leaves the role on Wednesday, less than a week after she unexpectedly quit.

“I leave with a greater love and affection for Aotearoa New Zealand and its people than when I started,” Ardern said. “I didn’t think that was possible.”

Beaming and at times emotional, Ardern was speaking at the annual birthday celebration for the Māori prophet Tahupōtiki Wiremu Rātana, founder of the Rātana faith. The event is the unofficial start to the political year in New Zealand, and sees leaders of New Zealand’s political parties converge on the eponymously named North Island village, along with followers of the faith.

Ardern was the star of the show, even as Labour’s Chris Hipkins – who will be sworn in as prime minister on Wednesday – and opposition National leader Christopher Luxon appeared to accuse each other’s party of sowing fear or division on Māori issues in their speeches.

The Rātana church has strong historical ties to Labour, but even for someone of her political affiliation, Ardern received a particularly rapturous welcome, arriving wearing sunglasses and a korowai – a Māori feathered cloak – to cheers, hugs, and requests for selfies. She had not intended to speak at the event, she said, but her hosts had rejected that plan.

In a brief speech, Ardern appeared to reject speculation – which has been widespread in New Zealand since her resignation – that the sexist abuse and vitriol she faced in the job had prompted her to quit.

“I want you to know that my overwhelming experience in this job, of New Zealand and New Zealanders, has been one of love, empathy and kindness,” she said. “That is what the majority of New Zealand has shown to me.”

A number of Māori leaders used the moment to express their support for Ardern as a leader and person, while remaining critical of some policies.

“I wear my political allegiances here,” said Che Wilson, Māori party president, pointing to indigenous designs patterning his attire, “but prime minister, it is only right that we say thank you.” As the crowd erupted into applause he continued: “Again, thank you.”

“The attack on families because of political decisions is just unacceptable,” said Rahui Papa, of Tainui. “[You’ve said] there is no petrol left in the tank, but the petrol pump has always been there. We would have helped you prime minister – and we will help you in future.”

Ardern would always be welcome at Rātana, he said to “return time and time and time again.”

Rātana celebrations are not traditionally a place for overtly political speeches, but on Tuesday, some bucked the trend.

Luxon used his time on the marae (meeting place) to decry Ardern and her government’s adoption of so-called “co-governance”, a term used to refer to shared management of affairs between iwi (Māori tribes) and the government.

Supporters of the policies say they affirm New Zealand’s founding document, the Treaty of Waitangi, which Māori and the British Crown signed as partners in 1840. Ardern’s government has applied them to ensure Māori representation in local government, establishing a Māori health authority, and developing a new framework for water management.

But the phrase has become a political lightning rod, with opposition to it among some New Zealanders in part responsible for Ardern’s drop in the polls in the months before she quit.

“National does oppose co-governance in the delivery of public services,” Luxon said. “We believe in a single coherent system, not one system for Māori and another system for non-Māori.”

Luxon’s party believed in “creating an equality of opportunity”, he said. “We don’t believe in equality of outcomes.”

He mentioned his efforts to learn te reo Māori – an official language of New Zealand – and said he was “incredibly proud” of New Zealand’s treaty settlement process. But his speech otherwise redoubled National’s opposition to the Ardern government’s policies for Māori.

Hipkins also referred to his rudimentary te reo, which he said he was committed to learning, saying he had grown up in a time when Māori language and culture, and New Zealand’s history, were not taught in schools – a situation Ardern has tried to reverse.

“When it comes to the relationship between Māori and non-Māori, there’s often been too much uncertainty and too much misunderstanding,” Hipkins said. “In an environment of misunderstanding and uncertainty, it’s easy for fear to be cultivated.”

But Hipkins was otherwise tight-lipped on which of Ardern’s policies relating to Māori – including co-governance – he might change when he takes office. He has promised since his nomination as leader to “run a ruler” over the government’s entire work plan, and seemed to suggest in his first news interviews on Monday that co-governance policies were on his mind.

He struck a conciliatory tone in his Rātana speech, however, praising a sports park near where he grew up that had been well-managed under a co-governance strategy.

But on Tuesday, he wasn’t the focus: Ardern was.

Against a backdrop of celebrations on Tuesday, she told the crowd: “If you’re going to leave, I say leave with a brass band.”