Williams said the organised protest was for retail workers to "take a stand" and collectively voice the message that "retail workers deserve the living wage".
"The living wage needs to be come the new normal in retail. The current wages being paid in many retail companies are minimum, and that needs to change," Williams said this morning.
Kmart, hardware store Bunnings and Huckleberry, along with some New World stores, earlier this year committed to paying their staff the living wage. The union said it had also recently negotiated a pathway to living wage with Swedish fashion retailer H&M.
Countdown, Farmers and Cotton On, however, had refused to pay their staff the living wage, she said.
Williams said the union believed it was time "outlier" retailers committed to paying their sales staff wages above the minimum wage or just above.
"[Retailers] need to pay wages people can live off, not struggle on.
"The industries in which we negotiate; living wage and above are normal. We don't understand why retail workers should be the poor cousins struggling to pay their bills and ensure there's enough food on the table."
Wages in the retail sector have historically been low.
Chris Wilkinson, managing director First Retail Group, said the living wage was seen as aspirational for many larger New Zealand retailers, however the sector was navigating through "unprecedented challenges" following weaker consumer confidence and the sustainability of traditional store models.
"The retail market is itself experiencing epic disruption across many fronts including consumers shifting toward online purchasing, suppliers selling directly, discretionary spend shifting toward experiential purchases from products and continued creep in occupancy and operational costs and other dynamics that have potential to compromise future viability of retail as we know it," Wilkinson said.
"Movements in wage rates need to be aligned with greater productivity that retailers will have to achieve through either improved practices from their existing workforce or automation, which many are now adopting.
"This will have an impact on the number of future roles in the sector and the potential for younger people to get on the employment ladder (with fewer positions available)."
In the UK, increasing costs are reported as one of the reasons big brands there are reducing store counts and actively mechanising roles, Wilkinson said.