A study published in April 2008's International Journal of Health Geographics, which was carried out by the University of Western Ontario, compared the locations of supermarkets in the Canadian city of London, Ontario, between 1961 and 2005. It found that smaller food shops were being forced out of older neighbourhoods because the large supermarkets being built in increasing numbers in the suburbs had soaked up most of the trade.

The study identified ‘food deserts' as residential areas from which accessing quality, reasonably-priced food stores by foot and public transport was deemed to be most difficult. It found that people living in these areas pay almost twice as much for goods from convenience stores than those living elsewhere, and are more likely to suffer from bad health and a low quality of life.

"This study highlights some of the unforeseen impacts of these hypermarkets," said the FPB's Policy Representative, Matt Goodman. "It seems that we don't fully understand how opening these huge stores impacts a community's ability to support the people who live and work there. The Government must act to help foster sustainable communities in towns and cities across the UK, and promote local retailers and local produce."

Recently, the FPB urged the Government to intervene following the interim findings of the Conservative Party's Commission into Small Shops in the High Street, which called into question some of the supermarkets' business practices, such as using their greater buying power to undercut small shops, employing aggressive pricing tactics, their late payment of suppliers and sudden changes in payment terms. It reiterated a warning made in 2006 by the All-party Small Shops Group that most of the UK's smaller retailers could be forced to close by 2015 if the rate of 2,000 small shops closing every year continued.

The Competition Commission (CC), which is due to publish the final results of its own investigation into inequalities in the groceries market, shows that since 2000, sales in supermarkets have grown in real terms by 26%, by 19% in convenience stores, but specialist stores have experienced only a 1% growth in sales.

The FPB believes that the Commission's initial recommendations, including one that a greater variety of supermarkets should be built to drive down prices for consumers, will further undermine local communities in the long term.

"We have all experienced problems because of the supermarkets, especially since they started moving into areas they never have before," said FPB member Arthur Hardy, of Special Thoughts card and gift shop in Llangollen, Wales. "We have every right to complain when they overstep the mark. The Competition Commission is just nodding in our direction, and giving the big supermarkets what they want. It's worrying to see what's going on."

Another member of the FPB, Barbara Swarbrick, of The Croft Bakery, Preston, laments the impact that supermarkets have had on smaller businesses.

"The supermarkets have such buying power and there is not much I can do about it, especially when they sell a loaf of bread for 30p. We have to just keep going and going, and working more and more," she said. "Where I live, there are shops closing down all the time. There is nothing here now; I can't even get a paper delivered."