Labour leader Jacinda Ardern told crowds at a rally in central Auckland that "Labour will not rest until we have pay equity in New Zealand".
More than 100 people, representing more than 19 groups and organisations, turned up for a rally fighting for equal pay at the Suffrage Memorial in Khartoum Place, Central Auckland.
Ardern said political unity was needed on the equal pay issue.
"In 2017 there should be no such thing as a gender pay gap in New Zealand," she said.
"I am committing that Labour will not rest until we have pay equity in New Zealand."
Labour will make sure that the country's mental health workers are a priority when it comes to pay equity negotiation, Ardern said.
"The Pay Equity legislation the Government introduced this week will also be scrapped and redrafted when we are in office," she said.
"The current legislation means we will never again see a settlement like the TerraNova settlement, or genuine pay equity achieved for our sisters, mothers, daughters and granddaughters. That's just not right in 2017."
National MP Jo Goodhew, who also spoke at the rally, was booed by the crowd.
She responded: "It used to be that everybody's opinions were heard. I only ask that of you.
"Now I hear your voices, not all of the legislation is supported by you all, but you must know that we have a select committee process, you will have your say again."
Other speakers included Jan Logie from the Greens, Tracey Martin of New Zealand First and Cinnamon Whitlock from the Maori Party.
The group marched up Queen St to demand equal pay in female-dominated occupations.
It follows the success of the case of Kristine Bartlett who won a $2 billion settlement for aged care workers from the Government.
There are still serious concerns over the Pay Equity Bill, which narrowly passed its first reading in Parliament.
The Coalition is of the view that the legislation was a "step back" and that it would change the way future settlements are made.
Prime Minister Bill English said Labour's plans to scrap the Pay Equity legislation would mean enormous uncertainty.
He said he did not agree with Labour's claim that the rules for pay equity claims in the bill would mean there could be no future cases such as the Kristina Barnett case for aged care, disability and home support workers.
"There is no doubt some people want rules that they think are going to suit their case a bit better. We've gone with the principle that groups that look to have been systematically low paid over a long time, particularly where Government is the payer, are the priority groups to get fixed."
The Employment (Pay Equity and Equal Pay) Bill 2017 passed its first reading this week.
It sets out a series of comparators by which future claims are to be made by a female-dominated group of workers: first by comparison with men in the same business; and if no valid comparison is available, then men in a similar business; and if no appropriate comparisons can be found then in the same industry or sectors; and if no appropriate comparison can be found, only then can the women's work be compared to a job in a different industry.