In an era of global food crisis, buyers must stop driving British farming into bankruptcy with

their obsession with low prices

When supermarket bosses are invited to 11 Downing Street for briefings on food prices, suppliers need to worry. Subsequent governments have given the blessing to supermarkets to drive down what they pay to farmers to make food cheap and keep down the overall rate of inflation. In the current climate, this pressure can only intensify.

Pressed by John Humphrys on Today as to how the government plans to control food inflation, deputy PM Harriet Harman let slip that she "expects the supermarkets to play their part". Farmers understand only too well what this means. Asda CEO Andy Bond, recently gave the game away when he said that he intends to be "assertive" and "aggressive" with suppliers. Keep that up, Andy, and there won't be many British farmers left.

Speak to suppliers at the moment and you will find them defeated and depressed. Crippling animal feed and fuel price rises have eaten away at any remaining viability. Maybe the penny will drop belatedly when we start seeing shortages of UK-produced foods. Come autumn, we can certainly expect a scarcity of British pork. The once-staple bacon butty made from UK-reared meat, could become a niche item beyond the financial reach of many. And that's just for starters.

Our supply of British liquid milk is assured - for the time being - but less production may leave us rooting around trying to source milk for cheese and yoghurt. There's also the prospect of horticultural crops rotting in the fields because growers can't afford to pick them. Government policy restricting migration is hammering growers whose pool of seasonal labour from Eastern Europe is drying up. 

But while farmers decimate their herds and line up alternative employment, buyers are still behaving as though it is business as usual, and demanding impossible prices. No wonder the home pages of farming websites flag up 24-hour helpline numbers for the Samaritans and the Farm Crisis Network. 

Our political leaders and supermarkets must shake off their complacency. Global food shortages are here to stay. Our 20th-century obsession with cheap food must urgently be replaced with a 21st-century commitment to ensuring food security.

Like performing seals, supermarket buyers have been trained to strike the most ruthless deals with suppliers, but this only works when supply outstrips demand. Time to learn new tricks.n

Joanna Blythman is the author of Bad Food Britain