A trial campaign designed to encourage the re-use of plastic bags led to significant shifts in consumer attitudes.

A Waste & Resources Action Programme report in the wake of the Choose to Reuse pilot scheme last year will show that while 70% of those asked at the start of the campaign said they put all their shopping into free plastic bags, by the end of the campaign that figure had fallen to 58%.

While 53% said they had bought a 'bag for life' at the outset, by the end of the pilot this had risen to 61%.

Researchers also discovered that people carrying out medium-sized shopping trips were more likely to re-use plastic bags than those doing top-up shops or very large shopping trips.

The WRAP pilot ran at 100 Tesco, Asda, Somerfield, Waitrose, Boots and Co-op stores in Bristol and Edinburgh for ten weeks from September. Staff wore badges and encouraged shoppers to re-use plastic bags or buy reusable bags. Roadshows and promotions backed the initiative.

The BRC said the pilot scheme had been "invaluable", adding: "It will enable retailers to refine their bag-for-life offers." WRAP earlier said that it was a possibility that the campaign could be rolled out nationally.

Environmentalists claim that 100,000 tonnes of plastic bags are thrown away every year .

Retailers are responding to calls for action. In its ten-point community plan, Tesco has pledged to use 25% fewer carrier bags by 2008 and make all its bags biodegradable from September.

This week Total UK announced it was introducing biodegradable plastic bags across its network of 850 forecourts. And Ikea has said it will charge 10p for plastic bags by the autumn.

However, the jury is still out on whether charging for plastic bags actually reduces their take up. In Ireland, consumption of plastic bags has risen dramatically since a levy on them was introduced four years ago (The Grocer, 3 June).