Asda is to remove all single-use plastic carrier bags from its checkouts.

From 1 June, bags will be placed under the direct control of each checkout operator, forcing customers to ask for a bag if they need one.

It follows successful trials in six stores. A new range of bags for life and reusable bags will be available in prominent positions at store entrances and checkouts.

"We want to make protecting the planet easier and more affordable for our 15 million customers and we believe this is the best way to encourage shoppers to change the habit of a life time and start reusing their bags instead," said Asda retail director Andy Clarke.