Tens of thousands of people have marched on New Zealand’s capital against a bill to redefine Maori rights in one of the largest protests in the country’s history.

Hundreds of people on Monday set out on a nine-day march to New Zealand's capital of Wellington in protest over legislation that would reinterpret a treaty at the heart of race relations in the Pacific country.

Tens of thousands of New Zealanders gathered outside the parliament in one of the country’s largest demonstrations to oppose the Treaty Principles Bill, which critics say undermines Maori rights and threatens race relations.