British fruit and veg has helped drive the first substantial fall in food prices in 12 months.

Latest figures from The Grocer Price Index show prices at the big four supermarkets fell 0.4 percentage points in March, although they remain 18.2% higher year-on-year.

The fruit and veg category had endured heavy price rises in recent months due to the weak pound and poor Spanish harvests. Cucumbers had doubled in price, lettuce and broccoli cost nearly 50% more year-on-year and carrots were up by more than a third compared with a year ago.

As the British harvest of several of these lines hit shelves, prices have started to recover and last month overall fruit and veg prices fell 2.8%. Many UK crops enjoyed a good harvest this year and will avoid the significant effects of the weak pound.

Experts warned that although inflation may fall, food would not return to 2007 prices. "Prices won't fall," said Mike Ader, business development director for English Food and Farming Partnerships. "Markets are still tight and demand for key crops is growing fast. Even with deflation, food will be less affordable as incomes are falling. The focus for the next 18 months will stay on pricing and promotions."