A union is demanding an apology after its members were told they were expected to work on Waitangi Day if they weren't New Zealanders.
The email was sent by construction company CPB Contractors to staff working on the Transmission Gully motorway north of Wellington.
It's not a message road workers were expecting the day before a national holiday.
"If it was a mistake, it was a bad mistake and if it wasn't a mistake, it was a shocking thing to happen in any workplace," Maurice Davis of Amalgamated Workers Union told Newshub.
An email from CPB Contractors to engineers working on the Transmission Gully motorway read: "It is my expectation if you are not from New Zealand then all engineers should be in work tomorrow and use this day to catch up."
Some of the workers complained to their union.
"They interpreted the email as they had to attend the work and I am talking about the visa workers predominantly from the Philippines," Davis said.
CPB Contractors is one of the companies building the $850-million dollar Transmission Gully, as part of a public-private partnership involving the New Zealand Transport Agency (NZTA).
NZTA said it's disappointed by the email from CPB Contractors and will be addressing it with them.
It said it's important anyone working for or on behalf of NZTA is able to celebrate Waitangi Day should they choose to.
Law expert Bill Hodge said employers can't treat workers differently based on their nationality.
"I found it very discriminatory in the way it was expressed and I think I would have been upset by it," Hodge told Newshub.
"It is the sort of stupid comment which should be revised and corrected rather than heavy-handed judicial punishment."
CPB declined to comment to Newshub but it has been in contact with the union.
The Amalgamated Workers Union Secretary said an apology from the company would be the first step to making amends.
"Waitangi Day is our national day but it's a day for everybody to enjoy, not just New Zealanders," Davis said.