Union wants apology after non-NZ contractors told to work Waitangi Day

A union is calling for an apology to roading workers who were told they were expected to work Waitangi Day if "not from New Zealand".

Engineers working on the $850 million Transmission Gully motorway north of Wellington, a public-private partnership involving the NZ Transport Agency, were sent an email on Wednesday discussing who could have Waitangi Day off.

"It is my expectation if you are not from [New Zealand] then all [e]ngineers should be in work tomorrow and use this day to catch up," the email read.

"If you are from [New Zealand] and Waitangi Day is just another public holiday then I would appreciate if you are also at work.