The debate was prompted by a motion filed by the ACT Party, which initially asked for MPs to consider whether the ethnic minority is "suffering crimes against humanity and genocide". The motion's wording was diluted, however, with ACT saying Labour wanted 'genocide' removed. 

During the debate on the motion in the House, van Velden said "we know that a genocide is taking place" with "voluminous" evidence from mutliple, credible sources. 

China has always denied it is abusing the indigenous people and say camps in which up to 1 million Uighurs are thought to be confined are for vocational education and terrorism, not forced labour and torture as reports suggest. 

Van Velden said on Wednesday that while some Uighurs have engaged in terrorism, genocide is not a justifiable consequence.

She noted that New Zealand and China have ratified the UN Genocide Convention, which defines genocide as any of several acts "committed with intent to destroy, in whole or in part, a national, ethnical, racial or religious group". Those acts include killing members of a group, causing serious bodily or mental harm to members of a group or imposing measures intended to prevent births within a group.

"Not one, but each of these are occurring in Xinjiang according to multiple sources. To take one example, there has been mass imposition of contraceptive devices upon Uighur women, and forced sterilisation, matched by an enormous reduction in fertility rates in Xinjiang."

Van Velden said normally she'd believe a court should decide what is or isn't genocide, something overseas governments have called for when deciding against labelling China's oppression of the Uighur people a genocide.

"But let's be honest, the perpetrator of a genocide is not going to submit to a court hearing. Our  conscience demands that if we believe there is a genocide, we should say so," the ACT MP said.

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The Greens' Ghahraman tried to have the motion altered to include the word "genocide", but was unable to due to a procedural issue. Van Velden earlier had the word "possible" removed from "possible severe human rights abuses", as the motion previously said.

Ghahraman used her speech to say the Green Party "unequivocally condemns the grave atrocities being suffered by the Uighur minority" and thanked van Velden for bringing the debate to the House. 

The MP regretted the final motion was "watered-down" and that Parliament "has shied away from talking about atrocity crimes being committed by the government of China, but rather what we're now calling 'severe human rights breaches'."

"But what matters is not only our words of condemnation. It's not whether or not we recognise this as a genocide and not another atrocity crime. What matters is our actions."

She wants to see New Zealand stop the "trade of slave labour goods" from Xinjiang.

Ngarewa-Packer, co-leader of the Māori Party, also voiced support for the original motion which said "genocide" was occurring.

"We are pleased to see the point of order to stop this motion being watered-down before it was debated," she said. "We must never attempt to silence the atrocities of genocides, and that's happening to indigenous peoples. 

"We need to be calling out these atrocities for what they are, wherever they are happening in the world."

She went on to list other peoples facing which she says is genocide, such as those in West Papua. 

The New Zealand Parliament's decision not to grapple with the issue of 'genocide' distances it from the United Kingdom and Canada - both of whom have had their Parliaments declare genocide - and the United States, which has had two administrations say crimes against humanity are happening.

Van Velden said international parliamentarians had backed motions declaring genocide as they recognised a proper court process wasn't possible because China wouldn't allow unfettered access to Xinjiang for investigation. 

"The British Parliament had a debate about genocide. Here in New Zealand, other parties, who had the power of veto would not allow this debate to proceed if the motion mentioned genocide… I started with the same motion as the British, then had to dilute it and soften it to gain the approval of New Zealand's governing party." 

In her contribution to the debate, Foreign Affairs Minister and Labour MP Nanaia Mahuta said the Government had consistently raised concerns about activities in Xinjiang, including to Chinese President Xi Jinping. 

She said the Government hadn't formally designated the situation a genocide, not because of a lack of concern, but because such a determination should only be reached "following a rigorous assessment on the basis of international law". 

"International courts have required fully conclusive evidence before reaching a conclusion of genocide," she said. 

"The New Zealand Government, in concert with others, will continue to call upon China in the strongest terms to provide meaningful and unfettered access to the United Nations and other independent observers to ascertain the situation in Xinjiang."

However, during an event on Friday evening, Chinese Ambassador to New Zealand Wu Xi suggested any visit to Xinjiang by observers would have strict conditions. 

"The purpose of the visit should not be an investigation or accountability with the presumption of guilt. This should not be the purpose," she said. "China is a sovereign country and people need to respect China's sovereignty and they need to comply with all the laws and regulations in China."

Wu said she doesn't believe there "is any absolute, unfettered access anywhere in the world" and repeated China's assertion that there are no human rights abuses occurring in Xinjiang. 

National's Todd Muller also spoke during Wednesday's debate, in which he reflected on the New Zealand-China relationship and how the two countries' ability to engage and discuss issues was important to their "ongoing peace and prosperity".

He said the depth of the countries' relationship allows each to raise concerns.

"It has meant we can have a frank discussion as two peoples who do not always agree, but who have respect for each other and a willingness to listen, and where necessary, to be criticised."

Muller said New Zealand walks its own path and has its own voice. 

"We do not seek to grandstand. But neither do we shirk from uncomfortable conversations, and, today, this House speaks in one voice with our concerns about severe human rights abuses in China."

Prior to the debate, Prime Minister Jacinda Ardern said she was pleased Parliament had reached a cross-party statement, unlike in other countries.

The motion:

"That this House is gravely concerned about the severe human rights abuses taking place against Uyghurs and other ethnic and religious minorities in the Xinjiang Uyghur Autonomous Region, and that it call on the Government to work with the United Nations, international partners, and to work with all relevant instruments of international law to bring these abuses to an end."