The Welsh Assembly's proposals for a charge (Convenience Store, July 10) were criticised by retailers who believe voluntary measures to reduce bag use are working. Their claim was backed up by government figures released last week which show that the seven largest supermarkets have reduced bag usage by 48% since 2006.
However, environmental groups have challenged the Scottish government to bring in a charge to reduce the one billion plastic bags handed out annually in the country.
They point out that the government has the power to introduce a retail levy thanks to the recent passing of the Scottish Climate Change Bill.
A spokesman for the Scottish government said that ministers had made it clear that they preferred the voluntary route to reducing use.
Northern Ireland's environment minister Edwin Poots said that he would consider a plastic bag tax if the existing voluntary arrangements did not lead to a significant reduction in plastic bag use.
Wholesaler Henderson's has introduced a charge at 13 Spar stores throughout Northern Ireland as part of a trial scheme which will last three months, followed by a planned rollout throughout the province.
All money collected through the scheme will be donated to the NSPCC.
The Association of Convenience Stores (ACS) and the British Retail Consortium both oppose a mandatory levy.
ACS chairman James Lowman said: "A bag tax will make people think twice about popping into the local shop, and the result will be more dedicated and car borne shopping trips. In this event the bag tax would actually do more harm than good."