The Government is expected to announce a ban on plastic bags today

Associate Minister for the Environment Eugenie Sage is set to make a "significant" announcement on the environment in Wellington this morning.

Earlier this year Sage said it was her preference to ban single-use plastic bags and said she wanted to phase them out rather than put a levy on them.

Companies around the country have been announcing the end to the use of single-use plastic bags throughout the year.

In June, 12 companies marked World Environment Day by committing to using 100 per cent recyclable packaging by 2025.

New Zealand-based Foodstuffs, Countdown, New Zealand Post and Frucor Suntory, and multinationals Amcor, Danone, L'Oreal, Mars, PepsiCo, Coca-Cola, Unilever and Nestle signed the NZ Plastic Packaging Declaration.

Countdown, Fresh Choice and SuperValue announced they would phase out plastic straws by October 1 this year and move towards 100 per cent reusable, recyclable or compostable packaging by at least 2025.

Countdown's general manager of corporate affairs Kiri Hannifin said that by phasing out plastic straws the company would be removing 11.6 million of them from landfills every year.

Foodstuffs was also trialling asking customers to bring their own containers to Howick New World to be filled with meat from the butchery or seafood.

L'Oreal last year replaced virgin materials with 7294 tonnes of recycled materials, an increase of 10 per cent on 2016. In 2017, the group's Redken, Kiehl's and Pureology brands for example, launched 250ml shampoo bottles made from 100 per cent recycled plastic.

Scientists estimate that more than 150 million tonnes of plastics are in the ocean and if nothing changes plastic in oceans will weigh more than fish by 2050.