ACT Party leader David Seymour has complained to Parliament's Speaker about the clothes worn by Green Party co-leader Metiria Turei.
Ms Turei wore a pink Public Service Association t-shirt emblazoned with the slogan "Worth 100%" across the chest, from a campaign for equal pay.
The t-shirt was teamed with a hot pink blazer, an outfit likely chosen to celebrate International Women's Day.
During a debate on pay equity, Mr Seymour requested a point of order, claiming Ms Turei's clothing was in breach of Parliament's dress code.
"Mr Speaker I seek your guidance with respect to Speaker's ruling 18-1 which refers to members wearing t-shirts and in particular, t-shirts with motifs on them in the House such as Metiria Turei currently is," he said in the debating chamber.
Mr Seymour was tactfully shut down by Speaker David Carter.
"Certainly I haven't had a good look at the attire the member is wearing," he replied, which was met with chortles from across the debating chamber.
"But it is the requirement that business attire is worn, I will watch it fairly carefully from now on," he said.
"Not too carefully, Mr Speaker," Metiria Turei replied.