The avalanche of lightweight plastic bags pouring into landfill and the environment is about to come to an end. Woolworths and Coles have announced a ban from mid-2018. Importantly this should also tell Australia's environment ministers who meet on July 28 that the time has come to pass legislation that will cover all stores.

It's been a long time coming. The last concerted effort was in 2005 when a voluntary code for a 50 per cent reduction agreed to by ministers and retailers was undertaken. It failed, with environment ministers admitting it was way behind schedule and the target of a complete phase out of plastic bags by 2008 was in trouble.

The supermarkets then slackened in their efforts and plastic bag use, landfills and littering began to grow again. Clearly a national law was needed – but the Commonwealth did not co-operate and it was left to individual states. South Australia, the Northern Territory, ACT and Tasmania acted.

That still left Queensland, NSW, WA and Victoria – four states that have been responsible for almost 1 billion bags being littered in the past 10 years.