麻豆约拍

The Big Four supermarkets are expanding at an unprecedented rate. It's being dubbed the new "space race", with Tesco, Sainsbury's, Asda and Morrison's fighting for dominance on high streets and shopping malls across the UK. But how can they keep on expanding, and slashing our food prices, when we're in the middle of a global downturn?

In a Panorama Special, reporter Paul Kenyon looks behind the cellophane wrappers and the "Buy-one-get-one-frees" to examine the true cost of our cheap food. He visits the mega-farms coming our way from the United States, with cows being kept indoors and milked on giant "dairy-go-rounds", and pigs housed in "sty-scrapers". He also takes a look at space-age greenhouses where fruit grows without soil.

The Big Four's UK expansion has never really been charted, until now. Panorama has pieced together the location of every new store currently being planned and built.

And as the production costs of our food are driven downwards, saving us pounds during the recession, Panorama carries out pioneering scientific research to discover whether "Made in Britain" always means what it says.