There was a strong show of support for South Island hīkoi participants as they arrived in Picton on Monday.
The participants are now due to cross the Cook Strait and unite with those already preparing to march on Parliament on Tuesday.
Up to 30,000 people are expected at Parliament when the hīkoi mō te Tiriti reaches central Wellington.
Commuters are warned to expect significant delays and university students have been told some classes will be moved online.
The demonstration is expected to dwarf the anti-Covid mandate protest that took over Parliament grounds in 2022.
"Every stop we have people join the hīkoi."
Butler told RNZ she looks at her daughter, who is nine, and hopes she won't have to be campaigning for Māori sovereignty when she's an adult.
"We've been fighting for over 200 years and I'm sick of it but I have to do it."
There will be extra buses and train carriages to ease congestion in the capital as the hīkoi arrives in Wellington.
However, commuters in the area were warned to allow extra time for travel and add several hours to their trips if needed.
