The dickeya disease has wiped out 20% of the seed potato crop in the Netherlands, forcing retail prices up.
Although so far only isolated cases have been reported in England and Wales, officials are concerned the disease will be hard to stop if it spreads.
Dickeya is often mistaken for the blackleg disease, but has more severe symptoms, rotting the seed tubers and causing plants to wilt and die. In the Netherlands, losses due to dickeya rose from 5m in 2002 to 25m in 2007, with figures expected to be at least as high this season.
Rising incidences are also being reported in France, Finland and Poland. Dickeya had been considered a warm weather disease, but it has now spread to cooler climates.
"The more we understand about dickeya, the more serious we realise the implications are for the British crop," said scientist Ian Toth of the Scottish Crop Research Institute. "We don't yet have a problem in Scotland, but it's an ongoing concern in England and Wales."
The Potato Council has advised growers to source seed through its Safe Haven Accreditation Scheme, which offers guarantees over seed quality.
Growers should be extra vigilant about the disease, warned Potato Council head of seed and export, Mark Prentice. "There needs to be a clear focus on protecting clean land, which may mean more compromise. The Potato Council will be working hard to ensure this is proportionate and fair."