Supermarkets in the Progressive chain will be pressured today to follow their rivals and charge for plastic bags.
The Warehouse today starts charging 10c for each plastic bag, and stores in the Foodstuffs supermarket group will start charging 5c a bag from August.
Representatives from the GetReal campaign will display a banner with hundreds of messages forming the words "no bags" in front of Countdown's Moorhouse Avenue store in Christchurch today.
They want Progressive Enterprises - which operates Foodtown, Countdown and Woolworths supermarkets - to also start charging for the bags now provided free at checkouts.
Foodstuffs, which owns New World, Four Square and Pak'nSave stores, is planning its charge as part of a campaign to reduce waste.
Campaigners said they would present Progressive with a petition of close to 1000 signatures asking it to stop giving away plastic bags.
A Progressive spokeswoman said the company had not decided what to do.
The Warehouse, Progressive, Foodstuffs and other retailers have signed a voluntary agreement with the Packaging Council reduce use of plastic bags.
The Packaging Council and the New Zealand Retailers Association have opposed calls for the Government to introduce a mandatory tax or ban on plastic bags, as the South Australian Government did in January.
The Packaging Council says the 2004 voluntary agreement has taken 100 million bags out of circulation and is on track to reach a 20 per cent reduction by July.
But GetReal organisers said a 20 per cent cut over five years was poor compared with Ireland and Taiwan, which reduced plastic bag use by more than 90 per cent through a small levy.
About a billion plastic shopping bags are dumped in New Zealand each year, and they have become a symbol of efforts to reduce waste, despite making up only a small proportion of waste sent to landfills.
In February, a survey of 2670 people commissioned by the New Zealand Business Council for Sustainable Development found just over half supported a ban on plastic bags.
Auckland city dwellers were particularly keen, 64 per cent supporting a ban.
But only 37 per cent of respondents supported a law requiring shops to charge 10c a plastic bag.
The Packaging Council says people would use more plastic bin liners if they cannot get free plastics bags to use as rubbish bags.
But GetReal organiser Sophie Ward of Sustainable Wanaka said the argument was a red herring.
"Even if you do use a bin liner, you need a lot less than one bin liner per plastic bag full of groceries."
The Packaging Council wants more effort to be put into increasing the number of bags that are recycled.