Supermarkets could provide the ideal environment for urban agriculture - and help reduce the growing carbon footprint of British cities, a leading architect has suggested.

At a Soil Association conference, Andre Viljoen, subject leader for architecture at Brighton University, said that more fruit and vegetables should be grown in an urban environment and urged supermarkets to take a proactive stance.

"Supermarkets need to reduce their ecological footprint by seriously stocking local food. I'd like to see them convert part of their car parks or roofs to market gardens that they could run themselves," he said. This would radically cut food miles, packaging, and, with gardens being organic, would also eliminate the need for oil-derived fertilisers and pesticides.

The idea is being developed by British cities including Middlesbrough and London, where the Thames Gateway is to feature spaces for production.