Despite efforts from campaigners, British supermarkets dished out even more plastic carrier bags last year than the year before - partly because the bags are flimsier than they've ever been.
New figures from waste advisory body WRAP show that 8.3 billion single-use bags were used in 2013 by customers of the seven biggest supermarket chains. While that figure's a third less than that for 2006, it's up 3.2 percent on 2012. On average, says WRAP, customers are using nearly 11 bags a month.
One reason is that the strength of the bags has fallen significantly - as many shoppers will know to their cost. Customers appear to be putting fewer items in each one to make sure they don't break.
"In 2013, total carrier bags (which include re-usable bags) weighed 67,300 tonnes, compared with 70,400 tonnes in 2012, which represents a 4.4 percent decrease," says WRAP. "Overall, there has been a 39 percent decrease in the weight of carrier bags from the baseline year of 2006."
Another reason for the increase in bag use is the rise of self-service tills, whch encourages shoppers to help themselves.
The Break the Bag Habit campaign group has been lobbying for the charge to be brought in sooner, and for the exemption for smaller stores to be lifted. Spokesperson Sue Kinsey says the new figures show the failure of voluntary measures to tackle the problem.
"This increase should not come as a surprise to government, as we pointed out the inadequacy of voluntary measures at the start of our campaign," she says.
"Frankly, the charge should have been brought in sooner, and the advice of experts, retail organisations and environmental groups to remove exemptions from the charge should now be acted on."
The introduction of a charge in Wales and Northern Ireland certainly seems to have had an effect. The number of bags used in Wales fell by 79 percent, after the introduction of a charge in 2011. Northern Ireland, which introduced a charge last year, also saw the number of bags used drop by 71 percent.
"Making a small change in our shopping behaviour by taking re-usable bags to the shops will prevent huge amounts of waste, litter and danger to wildlife," says Kinsey. "It will also help to reduce the yearly £1 billion clean-up cost of litter."