A 15p levy on plastic carrier bags proposed by the Welsh Assembly Government (WAG) would be a "draconian" measure that would penalise low-income shoppers, the body that represents retailers has claimed.

In its response to the WAG's consultation on the proposed bag tax, which closed yesterday, the British Retail Consortium described a compulsory charge on single-use carrier bags as "disproportionate and draconian".

It also argued that the charge, which has been proposed by Welsh Environment Minister Jane Davidson, would "punish" Welsh consumers who have already reduced their bag usage by almost half in recent years, according to figures from Wrap published in July.

BRC Business environment director Tom Ironside said that the WAG was "clearly determined to introduce a bag tax" and was consulting on how, rather than whether, it should be done.

"Customers will bear the brunt of the bag ‘tax'. Not only will it impose costs on shoppers it will increase delays at checkouts. But a bag ‘tax' will also impose pointless bureaucracy on the retailers who have to collect it," he said.

"The bag ‘tax' will hit low-income families hardest, as they are more likely to make frequent and smaller shopping trips."

Ironside's comments come after the Carrier Bag Consortium described the proposed 15p charge as "the worst case of greenwash it had ever come across" when the consultation launched in August. 

Sainsbury's chief executive Justin King has also publicly criticised the environmental lobby's focus on plastic bags, describing the items as a "poor measure of a supermarket's - and a customer's - real green-ness".