Hundreds of fans are expected to descend on the Corsham Sci-Fi day to see their favourite Star Wars and Dr Who characters and special appearances from the original film stars on April 17.

Corsham town centre will be invaded by extraterrestrial beings next Saturday as part of a family fun day which is set to raise thousands of pounds for the British Heart Foundation, 16-30 PHAB and Marie Curie Cancer Care.

Well-known characters including Daleks, Storm Troopers and Darth Vader will walk around the town collecting money for charity as well as meeting fans.

Co-organiser Ady Davies said: “It’s our second year and I think for our second year we have excelled ourselves. If everyone we have asked to turn up comes along, it will be massive.

“The stars will be signing autographs for £10 each.”

Film stars including Jeremy Bulloch who played Boba Fett and Richard Le Parmentier, who played Admiral Motti in Star Wars Episode IV: A New Hope.

Mr Bulloch and Frazer Hines, who featured in Dr Who, have offered to do several pictures with fans as part of an auction and raffle.

Mr Davies said: “We still need some more pledges of gifts from businesses to raise money for the charities.”

Sci-fi author David Johnson will be revealing his new novel Dark Victory at the event.

The novel is the final part of the Crystal Quest series, and although it is being officially launched at the London Book Fair at Earl’s Court on Monday, April 19, the Devizes-based author has offered to give away advance copies as prizes at the sci-fi day.

“I thought that it would be great idea if I was able to have some advance copies of my book available at the event,” he said. “I have written several children’s interactive short stories for the Corsham event again this year and my new books will be among prizes at the event.”

The event, at the Corsham Community Centre, starts at 10am. For more details go to www.corsham scifi.co.uk.