New EU proposals would require member states to choose between three methods of reducing the waste from bags.
European Union member states could cut their plastic bag use by 80%, the European commission has said, by charging for bags or even banning them.
Plastic bags are a major cause of seaborne pollution, which is a serious hazard for marine life, and some regions have already moved to cut their use through charging. The UK deputy prime minister, Nick Clegg, has pledged to bring forward charges in England that will affect single-use bags given out by supermarkets.
Bag use was cut dramatically by the Republic of Ireland after charges were introduced, a similar charge has recently come into force in Northern Ireland, and supermarkets in Wales reported a drop in use of up to 96% after a charging scheme was brought in two years ago. Scotland is bringing in a 5p charge next year.
The European commission is proposing a new directive that would require member states to choose between three methods of reducing the waste from bags: charges, national reduction targets, or an outright ban.
Janez Potočnik, environment commissioner for the EU, said: "We're taking action to solve a very serious and highly visible environmental problems. Every year, more than 8bn plastic bags end up as litter in Europe, causing enormous environmental damage. Some member states have already achieved great results in reducing their use of plastic bags. If others followed suit we could reduce today's overall consumption in the EU by as much as 80%."
Targeted reductions are seen as a relatively weak measure. In the UK, major retailers have pledged for some years to cut their use of bags, but the usage remains high, with about 8bn still given out each year. The EU estimates that every citizen uses about 500 plastic bags annually.
The packaging industry has responded by saying that most people use their plastic bags more than once, for instance using them as bins, but that does not cut the overall use.
Critics said the European commission's proposals did not go far enough and allowed member states too much leeway by allowing them to set their own targets rather than EU-wide goals or clear measures that would cut bag use.
Margrete Auken, a Green MEP from Denmark, said: "While a European approach to reducing plastic use is long overdue, the commission is sitting on the fence with today's proposals. The failure to set out clear targets for reducing lightweight plastic bags will clearly undermine the prospect of ensuring a reduction across the EU. Instead, the commission is leaving it open to member states to decide how and to what extent they seek to reduce plastic bag use."
When plastic bags, or pieces of them, find their way into the seas, they are a major hazard to marine life. A whale found dead on the southern Spanish coast was found to have swallowed 17kg of plastic waste, including plastic bags. Fish, seabirds and mammals can all ingest plastic, which they cannot digest and which can clog up their guts or cause choking.
The EU estimates that there are 500 tonnes of small pieces of plastic, made up of as many as 250bn individual particles, floating in the Mediterranean alone. In the Pacific, a massive area estimated at millions of miles across is now occupied by a gigantic floating "garbage patch" made of small waste plastic particles.
One of the key problems with plastic bags is that they are so light and small that they easily escape into the environment, defying attempts to recycle them. The European commission has identified this as a key reason for cutting the use of the bags, and other plastic packaging. The first moves to legislated at an EU level were made in 2011, and today's announcement is likely to take at least two years to put into practice.
According to the most recent estimates, from 2008, the EU produces 3.4m tonnes of plastic bags in a year.