Tourism chiefs claim American and Japanese tourists are cancelling trips to Britain because they fear catching mad cow disease from the foot-and-mouth epidemic.
One leading US tour operator said Americans with short attention spans are confused about the crisis and are scared of travelling to the UK.
He spoke as international travel bosses set off from Heathrow on a tour of British attractions in a bid to demonstrate that the UK is open for business despite foot-and-mouth.
They will visit Aberdeen, the Scottish Highlands, Edinburgh and Cumbria in the four-day trip organised by the British Tourist Authority to dispel misconceptions abroad that Britain has stumbled to a halt.
Brian Stack, vice-chairman of the US Tour Operators Association, estimated as many as 100,000 Americans could cancel their UK holidays this year.
He said: "My own company has had 2,000 cancellations in five weeks. Most Americans have mixed up foot-and-mouth and mad cow disease. Their attention span is not huge and all they know is there's a problem and they see lines of burning animals on the TV and are simply afraid to come.
"They want nothing to do with it. I want to be able to go back and tell the other tour operators in the US that their clients can come over here and have the usual great time."
The Japan Association of Travel Agents estimates about 20% of the 600,000 Japanese who visit Britain every year could cancel.
Managing director Koji Shinmachi said: "Many people are scared because they think foot-and-mouth is the same as mad cow disease. UK holidays are very popular among Japanese people and it's important for us to get the message across that it is safe