In a shock announcement on Friday afternoon, Woolworths and Coles revealed they would shortly begin phasing out the bags across their stores, with a total ban in place by June 30 next year.

The move has been welcomed by environmental groups, which have long campaigned for a national plastic bag ban, and has reinvigorated calls for the state government to legislate a ban. 

“It's a lot of hard work finally coming together, it’s really exciting,” Take3 sea guardian Monica Mudge said. 

“There will be less plastic bags floating around that can end up in the ocean or clogging up our landfill. 

“It’s a really positive step towards change. 

“There is a lot of retailers getting on board, but I would love to see government make it policy.” 

The phase-out will bring stores for both supermarket giants in NSW, Victoria and Western Australia in line with those in other states and territories where plastic bag bans have been legislated.

South Australia, ACT, the Northern Territory and Tasmania have already implemented state-wide bans, while there are plans in place for Queensland to do the same next year.

“We currently give out more than 3.2 billion lightweight plastic bags a year and hence can play a significant role in reducing overall plastic bag usage,” Woolworths Group chief executive Brad Banducci said.

“Our customers can also expect further commitments in reducing plastic use in all parts of our supply chain, especially in fruit and vegetables … we feel this is an issue we need to take a stand on.”

It is estimated tens of millions of plastic bags end up in Australia’s waste streams every year and are frequently ingested by wildlife.

More than half the turtles around the world and two-thirds of some bird species found on Australia’s east cost have ingested plastics, according to CSIRO research.