The organisers are now warning fans without tickets not to turn up on the off-chance of getting in.

The three-day outdoor festival of rock, pop and acoustic music is run by folkrock legends Fairport Convention and takes place this Thursday, Friday and Saturday, August 9, 10 and 11.

In past years, the festival has reached capacity once it is under way, but this is the first time the event has completely sold out a week before the event.

"We really hate to disappoint fans," says Festival Director Gareth Williams. "However, the safety and comfort of festival-goers is always Fairport's paramount concern. Besides, the site capacity is limited by the premises license. If anyone without a concert ticket is thinking of coming along in the hope of getting in, they will be wasting their journey."

The organisers are also advising fans to be on the lookout for touts selling forged tickets or fake entry wristbands. "If anyone offers you a ticket or wristband, don't be fooled," says Mr Williams. "Report them immediately to our security staff at the festival entrances."

The festival has been running for more than 25 years. This year's unprecedented success is due to a particularly strong line-up of acts and the celebration of Fairport Convention's 40th anniversary as a band.

"We are planning an equally strong line-up for next year and we expect demand for tickets to be heavy," says Mr Williams. "We always advise our audience to buy in advance and festival-goers should mark their diaries now for August 7, 8 and 9 2008."

There is one consolation for disappointed fans, however.

Tickets are still available for the famous pre-Cropredy 'warm-up' concerts featuring Fairport Convention and some of the musical guests who will appear at the festival itself.

This year, the concerts take place tonight (Monday), tomorrow and Wednesday at Woodford Halse Social Club.

As well as the current line-up of Fairport, great names like Richard Thompson, Ashley Hutchings and Jacqui McShee's Pentangle will be playing. Tickets are available at the venue each evening, priced £20.