Waitrose has won exclusive rights to sell a new variety of giant avocado called Nature's Haas.
Bred by Westfalia, one of South Africa's best known grower exporters, the fruit went on sale in 60 selected stores this week.
As this is the first year for commercial production, European manager Simon Curry expects supplies to be available for four to five weeks.
He said: "The variety is different from the traditional Haas and grows very large. Whereas the normal count size sold by multiples is around 12 to 14, this is an eight. Another characteristic is that it is less likely to discolour when cut."
Meanwhile, crop projections for the Mediterranean point to a shortage of the green Fuerte variety grown in Spain and Israel.
According to trade sources, availability could be slashed by half. Haas, which is picked later, appears to be unaffected.