Police say about 42,000 people gathered at parliament in the last stage of the nine-day protest in opposition to the Treaty of Waitangi bill

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A protest march estimated to be one of the largest in New Zealand history arrived at parliament on Tuesday, to oppose a controversial bill that could drastically alter the way the country’s founding treaty between Māori and the crown is interpreted.

After midday local time, police said parliament grounds had reached capacity as more than 35,000 people were estimated to be taking part in the march. As the first group of marchers reached parliament, the crowd stretched around 2km through the city.