ales of organic food have experienced a dramatic slowdown in the past year - mainly caused by severe supply shortages.

Sales were up 9.3% to £3.1bn in the year to

25 March, nearly half the 17% growth rate seen the previous year, according to TNS Worldpanel.

Growth was being hindered by a shortage of supply, particularly in dairy, meat and produce, said Greg Parsons, marketing controller in the liquids department at Dairy Crest.

The problem was being exacerbated by rising demand for organics.

"There is a fine balance between supply and demand - and momentum is lost when organic milk is not on shelf," he added.

Helen Browning, food and farming director at the Soil Association, and founder of the Helen Browning bacon and sausages range, said she believed the shortage of domestic organic product was illustrated by higher volumes of imported organics coming into the UK.

She admitted her company had been forced to import pigmeat from Sweden to meet demand.

This shortage of domestic organic food was deterring some consumers from buying into the category, said Richard Cullen, research and insight manager at the Meat and Livestock Commission.

"Research has shown one of the things organic consumers look for is a 'made in Britain' label. And one of the things that's holding growth back is a lack of UK farm conversions."

One factor preventing conversions was the cost of organic farming, said experts. Organic pigs, for example, cost 80% more to rear than non-organic pigs due to the high price of organic feed.

But things are looking brighter in dairy.

A further 85 million litres of organic milk will become available next year, according to organic milk co-operative OMSCo, which said this would be enough to balance demand and supply.

TNS figures showed sales of organics in other categories, including ambient groceries and alcohol, had improved.