New Zealand retailers - big and small - have welcomed the Government's plans to phase out single-use plastic bags over the next year.

Prime Minister Jacinda Ardern this morning announced it would introduce the ban, saying it was necessary to preserve New Zealand's clean, green reputation.

READ MORE: Government bans single-use plastic bags

"We're phasing-out single-use plastic bags so we can better look after our environment and safeguard New Zealand's clean, green reputation," Ardern said.

"Every year in New Zealand we use hundreds of millions of single-use plastic bags – a mountain of bags, many of which end up polluting our precious coastal and marine environments and cause serious harm to all kinds of marine life, and all of this when there are viable alternatives for consumers and business."

Supermarket giant Countdown, owned by Woolworths NZ, is supporting the ban.

Countdown corporate affairs general manager Kiri Hannifin said the phase out of plastic bags would have considerable flow-on benefits for the environment.

"We are absolutely thrilled the Government has begun consultation on a mandatory phase out of single-use plastic carrier bags in New Zealand," Hannifin said. "There is a growing sense of urgency that more needs to be done to address [plastic pollution].

"A nationwide phase out will go a long way towards stemming the flow of plastic ending up in our waterways, reduce pressure on recycling systems and provide a stronger basis for New Zealanders to change our attitudes and behaviours towards plastic use and plastic waste."

Countdown was the first New Zealand supermarket to commit to phasing out single-use plastic bags by the end of 2018, in October last year.

Since then a string of other supermarket brands and other retailers such as Mitre 10 and The Warehouse have committed.

New Zealand's largest retailer The Warehouse Group, which operates Noel Leeming, The Warehouse, Warehouse Stationery and Torpedo7, today announced it would say goodbye to plastic bags offered at its checkouts.

"This is a historic occasion for New Zealand's environment and we're very proud to be standing alongside Prime Minister Ardern and associate environment minister Eugenie Sage as they propose this legislation," Pejman Okhovat, chief executive of The Warehouse and Warehouse Stationery, said.

The group said it would begin to offer a range of pay-for plastic-free reusable bags.

In 2009, The Warehouse introduced a charge for single-use plastic checkout bags.

Foodstuffs, which operates Pak'nSave, New World and Four Square as well as Liquorland and bulk supermarket Gilmours, will stop offering single-use plastic bags from January next year.

Caroline Marr, director of small clothing retailer The Carpenters Daughter, also welcomed the ban.

"It think this is an awesome thing," Marr said. "I see what plastic is doing to our world and I've always cared for it."

The Carpenters Daughter offers recycled brown paper bags and makes her own cloth bags out of fabric scraps.

Marr said she did not believe the ban would negatively impact other small businesses. "It won't be a problem at all for small retailers because being small you are more individualised."

Steve Anderson, managing director of Foodstuffs NZ, said the Government's plans for a ban would put everyone in retail on the same page.

"We've given away millions of bags and we'll continue to encourage Kiwis to get creative and hunt high and low in their homes, garages and garden sheds to find bags or containers they can clean up and re-purpose for their groceries," Anderson said.

"It's important we acknowledge that some customers may take a bit more help to get there. We're going all out to ensure that we have very affordable reusable bag options available in our stores."

The Packaging Forum said the phase-out of plastic bags, biodegradable and compostable bags would level the playing field for the retail sector.

"Around 10 per cent of the number of bags which we collect are single use shopping carrier bags. These bags are not just from supermarkets, but a wide range of retail chains as well as dairies," Lyn Mayes, manager of the Forum's soft plastics recycling scheme, said.

She said the ban would have a positive impact on its recycling scheme which aims to recover 35 per cent of all plastic bags in New Zealand by 2025.

New Zealand does not have a standard for compostable packaging.