The state government will continue to rely on the supermarkets to ban plastic bags despite the flip-flopping from Coles, which had to bow to pressure and will start charging for bags later this month.

NSW is the only state in Australia to not ban plastic bags but the government will not move to phase out bags following a self-imposed "ban on bans" in late 2016.

Former premier Mike Baird demanded an end to "nanny state bans" after a humiliating reversal on his government's plan to kill the greyhound racing industry in the state.

Coles was forced into another backflip on Thursday and committed to charging 15¢ for bags from August 29 after the supermarket chain angered environmentalists by saying it would give bags away for free indefinitely while customers got used to bringing their own.