Six tickets to the live relay of the concert have been offered for sale

Interest in what could be the opera stars' last performance together in the UK has been high since the open-air concert, in the city's historic Royal Crescent, was announced in June.

Demand for tickets for the concert itself far outstripped the 7,000 available, so the local council is to set up two giant screens in nearby Victoria Park to allow more people to see the show.

Entrance to the park will also be ticketed, and all 20,000 places have been allocated, but now some of these tickets - which were supposed to be free - are appearing on internet auction site eBay.

Postal ballot

Six tickets for the live relay of the classical concert on 7 August have been posted up on the website and are poised to sell for between �21 and �25.55.

The show could be the Three Tenors' last in the UK

The Three Tenors concert is thought to be the last time the singers will perform together in the UK before Luciano Pavarotti retires in 2005.

It has been organised by YTL, the parent company of local utility firm Wessex Water.

Tickets were allocated by postal ballot, and Bath and North East Somerset Council is warning people without them not to attempt to get in to the show.

The council is asking those who do have tickets to travel by public transport if possible as parking near the event will be limited - a special park and ride service will be operating.