In the state of environmental emergency that we are in, still the single use of disposable plastic bags is prevalent; and while supermarkets do have a charge for plastic bag usage, it is not enforced in all retailers, such as wholesale and small shops.
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In 2015, a levy was introduced that banned any retailer with 250 or more full-time equivalent employees from giving out plastic bags for any less than a 5p charge per bag. The impact of this was significant, reducing the number of plastic bags given out by 90% within the country's 7 biggest supermarket chains.
However, this is far from enough, for instance in wholesalers, it is common practice for hundreds of triple ply plastic bags to be handed out to customers per day and never with a levy. Not only this but small shops have no obligation to charge for bags, giving no deterrent to people using them excessively.
So much more can be done to stop the pollution of the environment with plastic and this is a significant part of it.