Thousands of animals are shown at the show each year

David Walters said there was "absolutely no truth whatsoever" in the claims and described them as "irresponsible" and "malicious".

It is the second time the show has officially had to dismiss the rumours.

They surfaced when one day of the Royal Show in Warwickshire was cancelled last month due to heavy rain.

The four-day agricultural showpiece, which starts on Monday, attracted about 240,000 visitors last year.

Mr Walters said: "There is absolutely no truth whatsoever in these reports which increasingly appear to be the result of irresponsible rumour-mongering. I repeat that they are completely false and unfounded.

The rumours have become so persistent that they appear to be circulating with malicious intent David Walters

"In fact, the rumours have become so persistent that they appear to be circulating with malicious intent, but I want to assure everyone that the show is definitely on and that any suggestion that it might be called off has never been on the agenda."

Meanwhile, motorists throughout Wales heading to the show next week are being urged to share their vehicles to ease congestion and help the environment.

A database has been set up to link drivers with passengers, and it is also designed to help people travelling to work and those carrying out the weekly shop.

People sign up with a few personal details, log in and register journey details free.

The system will then search to find someone who is going in the same direction, leaving it up to travellers to make contact through a secure e-mail connection, and arrange to share both the journey and the costs of travel.