UK supermarkets face a major shortage of mushrooms this summer, industry experts have warned.

Growers in the key EU production areas of the Netherlands, Poland and Belgium no longer see the UK as sufficiently profitable following sterling's 11% fall in the past year and are considering targeting more lucrative EU markets such as France and Germany.

"There will undoubtedly be shortages of mushrooms if the foreign exchange situation does not improve," said Andrew Middlebrook, sales director at Monaghan Mushrooms and chairman of the Mushroom Bureau. "These issues are creating real pain. If they are not dealt with properly there will be shortages because producers will either shut down or look at alternative markets. The sterling price movement has cost growers and suppliers millions."

UK suppliers said they were willing to expand to meet demand, but a shortage of compost caused by high wheat straw prices meant UK production was now at maximum capacity.

Irish farmers, meanwhile, have claimed low retail prices are forcing them to scrap production.

John Smith, MD of UK supplier Greyfriars, called on retailers to support growers by increasing the amount they pay them. "We need an 8%-10% increase in price. It's almost a given there will be shortages in August if there isn't an increase. The Irish guys, especially, are in trouble. It's a serious state of affairs."

Only 28% of the £300m of sales through UK retailers come from domestic producers. The rest are imported, with 35% coming from the Republic of Ireland, 30% from the Netherlands and the rest from Poland, the Netherlands and Belgium.

The problem has been compounded by the fact that the European industry is only just recovering from an oversupply crisis that forced prices down. This was prompted by the rapid expansion of Polish production coupled with a fall in demand for processed mushrooms.