Hordes of Daleks, the pepper pot shaped arch-enemies of Doctor Who, famed for their tinny battle cry of "Exterminate", will gather at Longleat next month.

The Daleks will join the TV cult hero for the 10th annual Doctor Who Day on August 3.

Organisers hope hundreds of fans will turn up for the family event, which also marks the

40th anniversary of the first episode of the BBC series, shown in 1963.

Longleat's public relations officer, Florence Wallace, said: "Doctor Who Day is always incredibly popular and we're hoping this year's event will be the biggest and best ever."

Colin Baker, the sixth Doctor Who actor, will cut an appropriately themed cake and blow out 40 candles.

Sophie Aldred, who played Ace, and John Lesson, the voice of robotic dog K9, will also be attending the event, which draws Doctor Who fans from far and wide.

Longleat has been home to England's only permanent Doctor Who exhibition for 30 years.

It has also been hosting Doctor Who family days for over 10 years.

Although the organisers are trying to bring together more Daleks in one place than ever before, visitors should look out for a variety of other monsters such as the dreaded Cybermen patrolling the estate.

To mark the event, BBC Worldwide has joined with Longleat to run a competition to find the most appropriate collective noun for a group of Daleks.

To enter the competition, send suggestions to Dalek Competi-tion, Room AG250, BBC Woodlands, 80 Wood Lane, London W12 OTT.

The closing date for the competition is August 1.

The winner will be announced at the event.