Poor weather during the key Spanish and Canary Islands growing seasons has hit import volumes, while premium Italian supplies have been struck by the yellow leaf curl virus.
The weakness of sterling had also prompted some European suppliers to look for more profitable markets than the UK, claimed British Tomato Growers' Association executive officer Gerry Hayman.
The shortage comes at a time when UK growers have been reducing volumes and questioning the profitability of supplying the market, Hayman said.
The UK only produces about 18% of the tomatoes sold in supermarkets each year, with the remainder imported from Spain, Italy, the Netherlands, Poland, Morocco and Egypt. But in one week in April, only 300,000 of an expected one million trays of tomatoes were shipped to the UK from the Mediterranean.
Many domestic producers have abandoned classic round tomatoes in favour of more premium products such as on-the-vine, baby plum and cocktail tomatoes, citing poor supermarket returns as the reason.
The Jersey Produce Marketing Organisation went under last year, while Wight Salads and Humber VHB had both reduced volumes for 2009, Hayman said. Even though additional volumes were coming through from Thanet Earth, overall UK projected volumes for this season were still 10% down on last year at 70,000 tonnes.
A Grocer 33 shopper visiting Sainsbury's in Farlington, Hampshire, this week, reported seeing in-store signs notifying customers that a switch from Spanish to British supplies was to blame for lower tomato availability and quality. Such shortages would become commonplace over the summer, particularly if hot weather boosted demand, Hayman said.
Tomatoes are the third-largest selling line in the fresh produce aisle, recording sales last year of £629m [Nielsen], behind only potatoes (£1.1bn) and apples (£630m).