One NZ workers are protesting the company's decision to increase mandatory office work days to three per week, after a work-from-home policy that was introduced during the Covid pandemic only required staff to come into the office for two of the five working days.

Unite Union's national secretary John Crocker defended the workers' stance on Summer Breakfast when asked what was so bad about only spending three days in the office.

"This is part of negotiation and this is the principle... we've got transport costs, emissions [and] the time spent on the road," he said.

"What we've seen is this wasn't necessary. We've been through Covid, we know these people can work from home, so the workers have said basically no, this is too much and you're asking too much of us and 'no thank you'."

The union secretary said during the pandemic it "was clear who the essential workers were".

"We also saw a lot of people who were working from home, there wasn't a productivity loss to the company," he said.

"The company came out when we did the press release last year and it said ‘this won't affect our customers’. It's like well, then let it happen. Like get to the table and negotiate with the workers. They're saying let's come in two days, not three, and that's where we're at today."

Crocker said the savings from not travelling to work each day were shared by society.

He said workers staying home weren't adding to Auckland's gridlocked traffic woes, while the planet was benefitting from their not burning fuel.

"It means everybody else gets to work faster but the cost falls on the planet when we're talking about emissions from vehicles, so no, we don't think the burden should fall on the workers."

The union said it was down to the workers to dictate what they considered a satisfying work arrangement, acknowledging office work had its perks but that workers needed the freedom to choose.

One NZ staff are also pushing for pay increases of 10 per cent, Crocker said, to match inflation.