ACT's leader David Seymour and the Jewish Council of New Zealand are asking Green Party MP Chlöe Swarbrick to explain herself after she used a sentence some say is anti-Semitic.
At a pro-Palestinian rally at the weekend, Swarbrick used the phrase "from the river to the sea, Palestine will be free".
The co-founder of Jewish Voice for Peace also used the phrase at the event, and many believe it's a cry for an independent Palestinian state to be formed.
Others believe it's used to call for Israel's destruction.
Swarbrick spoke to Corin Dann.
