Israel has been forced to slash fresh produce exports to the UK because of the damage done by the bad weather.

Unseasonally low temperatures, which hit -9C in the north and -7C in the valleys this month, have wiped out large swathes of tomatoes and potatoes, while strawberries, herbs and flowers have also been badly hit.

UK retailers are already seeing a reduced supply of strawberries and tomatoes, said Amos Orr, UK general manager of Israeli exporter Carmel Agrexco. The industry was still trying to establish the full extent of crop losses, but expected "millions of pounds" of lost sales in the UK, he said.

The value of Israeli fresh produce exports across the EU is estimated at £500m.

Aside from the direct impact of the frosts, plant maturation could also be damaged, Orr warned, adding that, in total, as many as 20 different types of fruit and vegetables could be affected .

Israeli growers have been forced to apply for state aid due to the level of devastation, said David Crossland, general manager of Arava Export Growers. "There will be a reduction in volume and quality for export, with marking on the skin more evident," he said.

Herbs would be worst hit, as visual markings rendered the produce unmarketable, but peppers had been less severely damaged.

Crossland said discussions were under way with retailers about lowering product specs, or altering pack contents in order to let more produce into the UK.

"This is unchartered territory," he said. "The Israelis don't have the systems and facilities to cope on a grand scale with this sort of weather. There is a lot of damage."

Outdoor-grown flowers have also suffered from the cold, with exports likely to be affected.

However, the full extent of damage to the categories was yet to be established, said a spokeswoman for Flowers Israel.