Environment

Asda wants to reduce carrier bag use by 20% by forcing customers to request them from checkout operators from the beginning of June.

Asda, which is part of Wal-Mart, said it was against charging for single-use bags because it went against the policy that "customers don't have to pay a premium to go green".

A spokesman said: "We don't think it's fair to add a levy that would make shopping more expensive."

The supermarket is to introduce a new range of reusable bags to coincide with the launch of its 'bag on request' initiative, which follows trials at six stores.

Asda said that, before June, it would retrain staff, talk to customers about the changes, and install new, more prominent units for reusable bags.

Marks & Spencer announced last week that it would start charging customers 5p for each single-use bag used in its food outlets from 6 May.

The target agreed between retailers and government in February 2007 is for a 25% reduction in the environmental impact of carrier bags by the end of this year.