Damage done to Britain’s farmland by the floods of the past two months could trigger a surge in supermarket prices of many seasonal crops and play havoc with the Bank of England’s attempts to quell inflation, economists believe.

Farmers across much of Britain face the prospect of sharp cuts in produce volumes for the rest of this year after some of the most devastating summer rainfall since records began.

The supply shortages could fuel already sharp recent increases in the cost of food on supermarket shelves and spark a resurgence in inflation just as it was starting to fall back towards the Bank’s 2 per cent target.

Last week, vegetable producers were already reporting feeble crops and low volumes.

Tim Mudge, of the Processed Vegetable Growers Association, said that only 90,000 tonnes of peas would be produced this year, compared with a normal yield of 150,000. Pea and lettuce crops were badly damaged by heavy rainfall in Lincolnshire and the Fenland areas in June, which was the wettest June for 150 years.

Last year, Mr Mudge said, drought meant that production fell short by 15,000 tonnes. “In reaction to that, we had retail price rises of up to 44 per cent,” he said. “We just don’t know what we’re going to be faced with in the future.”

David Piccaver, chairman of the British Leafy Salads Association, said that the soil in fields such as his had been saturated for six weeks, which meant that much of the lettuce that would be produced would be less long-lasting. Mr Piccaver said: “Harvesting costs have probably gone up by 10 to 15 per cent and we have also had a little difficulty getting the crops out of the field because it’s so wet. The fields are not fit to plant.”

The first of the lettuces planted at the start of the heavy rainfall were now being harvested and were proving less hardy than usual, Mr Piccaver said. By the end of autumn, volumes could be down by about 20 per cent.

“The supply situation will remain difficult for the rest of the season,” he said.

Economists are divided over the likely extent of the price effect from the floods’ damage to farming, but cited price jumps for produce seen after torrential rain in the autumn of 2000.

George Johns, of Barclays Capital, noted: “Six months afterwards, seasonal food prices rose by a very firm 9 per cent. At that time, the Office for National Statistics said that the ‘widespread floods had hampered planting and harvesting’ of seasonal foods . . . We would view the outlook for seasonal food price inflation as presenting an upside risk to inflation.”

Doug McWilliams, of the Centre for Economics and Business Research, calculated that crop damage could add as much as 0.5 percentage points to the inflation rate. He cited the precedent of damage to potato production in 1994-95, which he said pointed to a drop of a fifth in output this year, something that “should cause potato prices to double”.

A 0.5 point jump in consumer price inflation could even take this measure back into the territory that might force Mervyn King, the Bank’s Governor, to write an explanatory letter to the Chancellor - something that he must do if the annual pace of price increases climbs above 3 per cent.

Food prices have already risen very strongly in the past year, driven by rising demand from China and India, with the annual rate of increase reaching 4.6 per cent. George Buckley, of Deutsche Bank, said that food price inflation had been particularly sharp in the UK, at its worst for nine years.

Huw Thomas, of the Milk Development Council, said milk supplies had also been hit by the wet weather. Because rain washed away nutrients in the grass, cows were producing less milk. Grain prices meanwhile already had begun to go up, raising feed costs.

Not all analysts agree that grocers will respond to the supply shortage by raising prices. Richard Dodd, a spokesman for the British Retail Consortium, said: “There won’t be any shortages. Retailers have scope for sourcing goods from abroad. The difficulties of the flooding are actually quite localised.”