The Co-op is banning genetically modified products from all its businesses.

GM ingredients will be banned from the supermarket's own-brand products and the Co-operative Bank will not invest customers' money in GM technology, the group said.

The move follows last week's publication of the results of three-year field scale trials on the impact of GM crops on the environment.

The findings showed some varieties are worse for wildlife than other conventional crops.

Martin Beaumont, chief executive of the Co-operative Group, urged other businesses to follow the move.

"We have listened to the experts on both sides of the debate. We have consulted our customers and members and evaluated available evidence. But, on the strength of current scientific knowledge and the overwhelming opposition of our members, the Co-op is saying no to commercial growing of GM crops in the UK.

"And we would urge other consumer-led businesses to follow this precautionary approach. Too little is still understood about this technology and how it would impact on our environment in future generations.

"Let the science and research continue, but unless or until the case is convincingly made, the Government has a responsibility to keep the lid on commercial growing," he said.

A Co-op spokesman said the supermarket GM ban would not apply to products from other companies, just own-brand products.