The European onion crop has suffered heavily from the mix of hot and wet weather, threatening supply in the months ahead.

Spanish growers are reporting smaller bulbs than usual, although some may still be suitable for the demands of UK multiples. But rain arrived too late in Poland, where the onion crop could be half normal levels, while cloud bursts in Holland on an already light crop could push volumes down more than 25%.

In the UK skins have already set, and bulbs are now starting to swell again, which may be a forerunner of split skins. However, the rain has also pushed bulb size for the English crop up out of the danger zone that caused problems in July.

Bob Taylor, MD of Bedfordshire Growers, said: "We are desperate for fine weather with harvesting about to begin. Even if the crop does come back on course, there could still be mixed quality. Tonnage of larger bulbs will still be down as much as 15-20%."