From what I've been able to peice together, when the British signed their treaty with the Maori people, there were 2 versions: one in English, and one in the Maori language. Most of the Maori unsurprisingly signed the version in their own language. But apparently the translation between the two versions was not very good as for instance the English version says they submit to the sovereignty of the queen, while the Maori version says they retain autonomy.
These inconsistencies between the versions caused much consternation and heartburn between the Maori and NZ government so in the 70s they created a commission that is supposed to look at any places the two treaties differ in meaning and issue reports to the government on proposed legislation that might violate the Maori version of treaty, and address past violations. It doesn't seem like the commission's reports carry the force of law, but I gather that the NZ courts have adopted a posture of deference to them.
Apparently some people (I presume predominantly non-Maori) feel this commission has rather over-broadly interpreted the rights and privileges the non-english version bestows to the Maori people vis-a-vis the English version, and object that this fundamental undermines liberal democratic values like equal treatment under the law. So they have introduced legislation that would put rules in place for how the commission is allowed to interpret the treaty. AFAICT basically trying to legistlate originalism in their interpretation.
People opposed to the legislation are, somewhat predictably, calling the people who want the legislation 'racist'. Much ballyhooing ensues.