Labour leader Jacinda Ardern is promising to make Matariki a public holiday if re-elected.
Ardern made the pledge to mark the start of the Māori New Year while campaigning in Rotorua this morning.
"As I've travelled around New Zealand I've heard the calls for Matariki to become a public holiday - its time has come. It will also be a confidence boost that many sectors need right now.
"Matariki will be a distinctly New Zealand holiday and a time for reflection, celebration, and to look to the future as we take increasing pride in our unique national identity," Ardern said.
The last public holiday introduced was Waitangi Day nearly 50 years ago.
This move would mean New Zealand would have 12 public holidays and it would break up the winter period.
A group of experts will help determine an exact date but Ardern expected it would always fall on a Monday or a Friday within Matariki.
She said the new holiday would not take effect until 2022 to give businesses time to prepare.
Labour Party deputy leader Kelvin Davis said a Matariki public holiday would help domestic tourism and hospitality sector.
"As New Zealanders plan mid-winter getaways and will also allow the tourism industry to market Matariki globally to international travellers as a uniquely New Zealand winter experience in years to come."
Davis said Matariki would be the first public holiday that recognised Māori culture and tradition.
"Making Matariki a public holiday is another step forward in our partnership as a people and a further recognition of te ao Māori in our public life", he said.
In May, Laura O'Connell Rapira from Action Station set up a petition urging the government to make Matariki a holiday, and has since received nearly 35,000 signatures.
Māori astronomer Dr Rangi Mātāmua told RNZ in May that Matariki had increasingly become a part of our national identity, and making it a public holiday would encourage more people to learn about it.
"Matariki traditionally was a public holiday," he said.
"It was when Māori stopped working, they relaxed, they sat around, they ate together, they celebrated together. So us trying to reincorporate that into our modern society is a good thing, and I think it will help Matariki to endure."
Political parties react to Labour's vow: 'It's not leisure and holiday time' - Winston Peters
Green Party co-leader Marama Davidson said she was "pleased to see Labour coming to the party", with the Greens already announcing their support for making Matariki a holiday.
"The Māori New Year is a chance each year to reflect, celebrate, claim our past, and look forward. It gives us time to look up at the night sky and teach our kids about how our tūpuna used the stars to give guidance in how we live our lives," Davidson said.
"As well as increasing cultural awareness around our history, an extra public holiday will encourage New Zealanders to get out to the regions and support small businesses that have been hurt by the drop off in tourism."
However, New Zealand First leader Winston Peters wasn't impressed.
He said right now work, sacrifice and collective effort was required, not another holiday.
"Now is not the time, when we are in the throes of huge financial challenges to start thinking about a holiday. I'm sorry, work is going to be our way out of it, working smarter and working more clever than we did in the past - but it's not leisure and holiday time," Peters said.
National Party leader Judith Collins said the policy could hurt small businesses.
Collins said some of her team thought it was a great idea, but her concern was that it was another public holiday employers would have to pay for.
"People need to realise too ... that when we look at anything where there's extra cost, particularly on small businesses ... it's actually having a huge effect on the attitudes of people in small businesses in particularm," she said.
"We're going to have an awful lot of holidays for people that they weren't looking for - and those are unfortunately a lot of job losses."
She said she would like to see the evidence the new holiday would help domestic tourism.
National finance spokesperson Paul Goldsmith also said the policy was "tone deaf" considering the economic situation.
"More and more New Zealanders want to celebrate Matariki, but if it is to take the form of a public holiday it should replace an existing one.
"A new public holiday won't mean much to the tens of thousands of families who are now on the unemployment benefit."
ACT leader David Seymour accused Ardern of being in "la la land" for the policy vow.
"Anybody who thinks stopping people working will boost the economy is an economic illiterate, and small and medium enterprises can ill afford even more of this meddling," Seymour said.
He also questioned why Labour chose this as one of their first big campaign promises.
"It would be more honest for the Labour Party to say they have no policies than fly kites such as additional public holiday as their first policy announced in an economic crisis.
"There are 70,000 more people on welfare, future generations face mountains of debt, businesses are struggling to survive, and Labour's answer is a new public holiday.
"If Labour wants Matariki to be public holiday, it should abolish Labour Day so businesses aren't taking on more costs."