THE TAX on plastic bags is to be raised by at least 25% to counter the steady increase in their use by shoppers.

The bag tax could even be doubled to 30c if a government review finds that retailers have stopped charging the levy.

Existing legislation restricts Dick Roche, the environment minister, to a maximum rise of 4c on top of the present 15c, but he will ask the Dail to increase his powers.

Officials reviewing the effectiveness of the plastic bag levy are to report to him soon. They expect that €20m of bags will be sold this year, the equivalent of more than 130m being bought by the public.

The deterrent effect of the 15c levy has weakened over the four years of its operation. In 2002, shoppers spent only €7m on plastic bags in supermarkets and other stores. But sales rose to €12.6m in 2003, €13.5m in 2004 and €17.5m last year.

“I don’t want to see plastic bag use creeping back in,” said Roche. “The law permits me to increase the levy and I am disposed to doing that. I can only go to 19c under the existing law, and I will do that. But if necessary I will go back to the Oireachtas looking for support to go higher, and I will get it.”

His biggest concern was evidence that fast-food outlets in particular were abusing the regulations. “They have been using those stripey plastic bags with abandon,” he said. “There are very strict limits on when you can give plastic bags for free and there is some evidence that this is being breached. I want to stamp that out.”

Smaller plastic bags used to carry fresh meat, fish and poultry are exempt from the 15c levy, as are those used to store non-packaged goods such as dairy products, fruit and vegetables, confectionery, cooked food and ice. Airport, ferry and flight shopping bags are also exempt from the regulations.

Larger plastic carrier bags, favoured by some independent fast-food outlets, do not qualify for the exemption.

Roche said that Belgium and Japan are considering a ban on plastic bags and he has spoken to politicians in both countries about the success of the Irish system.

John Dardis, the Progressive Democrats senator, proposed raising the levy to 30c last week because of evidence that plastic bag litter is beginning to re-emerge across the country.

After the introduction of the levy, he said, the numbers of “stray bags” on streets, fields, tress and hedges had dropped dramatically. But some retailers now needed to be reminded of their obligations under the legislation. “I am not certain that all retailers are even asking shoppers if they want a bag anymore,” he said.

“Sometimes your goods are bagged before you get a chance to state your preference.”

Local authority waste enforcement officers police the levy but prosecutions are costly to pursue and fines can be small. The Virgin Megastore chain was fined €150 last June after its store in Tallaght was convicted of not charging the plastic bag levy.

The Department of the Environment said the proceeds of the levy go directly into a special ring-fenced “environmental fund” spent on recycling initiatives and promotion.

Times Recommends

• The Japanese Prime Minister is doomed: or is he?
• Brighton company 'involved in cyber attack'
• The art of survival: it’s all in the mind