We know them best as Emmerdale's amiable likely lads. Actor Dominic Brunt plays kindly country vet Paddy Kirk and co-star Mark Charnock is hapless but well-meaning Woolpack chef Marlon Dingle in the Yorkshire soap.

But this month the pair are unleashing their dark side - and unearthing the undead.

The unashamed zombie obsessives' are organising the first Leeds Zombie Film Festival, a 12-hour celebration of the cult horror genre. On April 20, from 12 noon to midnight, the actors will be screening six classic zombie films at City Varieties in Leeds. It may not be for the fainthearted, but it's all in a good cause - the World Society for the Protection of Animals.

"Mark and I are massive zombie fans," says Dominic. "I was looking for a way of raising funds for WSPA, so we came up with the idea of screening as many zombie films as we could over 12 hours. That way we could sit and watch them and raise money at the same time!

"There must other zombie nerds out there keen to take part in a zombie fest. We'll be introducing each film ourselves. It's going to be a great night out - but maybe not for the whole family.

"We're aiming to sell 500 tickets. If it works out we'll hold another festival next year and maybe have some special guests along."

Dominic and Mark hope to show half a dozen of their favourite zombie movies, old and new.

"We're still awaiting confirmation for the final list but it's going to include Night of the Living Dead, Zombie Flesh Eaters and Return of the Living Dead," says Dominic.

"It's a way of giving zombie fans chance to see classics from the past on the big screen for the first time as well as some more recent contributions to the genre that may have passed many fans by.

"The City Varieties is a brilliant venue as it's so old and quirky, with lots of history. We want people to come along for noon and leave at midnight, all twitchy and paranoid, wondering what creatures may be lurking in the dark."

So what is it about zombie flicks that gets fans into a flesh-eating frenzy?

According to Dominic and Mark, our love of all things zombie started in 1932 when the Halperin Brothers' White Zombie was released to unsuspecting cinema audiences.

"Audiences had been lapping up the blood with Bela Lugosi's Dracula movies and Boris Karloff's Frankenstein but were ready for a new monster," says Mark. "There was a fascination with Haiti and voodoo but there were deeper forces at work in 1930s America. As the stock market crashed and the Depression hit hard, zombies symbolised the powerlessness of the American workforce.

"Their new hell was a vision of blank-faced unemployment lines with a lost individuality and will. Zombies resonated with the American public. The brain-eating came later."

Hollywood capitalised on the new walking dead fascination, producing zombie movies throughout the Thirties, but it wasn't until 1943, with the release of Jacques Tourneur's I Walked With A Zombie, that the genre took off.

"It was a startlingly atmospheric shocker that returned the zombie to his Haitian roots," says Mark. "It went beyond the commercial zombie and introduced deeper themes of sexual repression, substituting physical attacks for psychological terror. It was a commercial and critical success.

"Years of similar movies came and went, with the zombie driven into pale B-movie imitations of Tourneur's creations. The biggest change came in 1968 with George A Romero's Night of the Living Dead. These zombies weren't the monsters audiences were used to, but reanimated human beings consuming survivors. They were friends and neighbours of the living.

"Handheld cameras and news reports' created a documentary feel, it was a million miles from old studio-based zombie films. Nothing was left to the imagination. Romero used animal organs which extras chewed on. Most zombie films that followed owed much to Romero."

Romero's ghouls represented what America was struggling to come to terms with, namely Vietnam. To America, zombies represented a fear of themselves. "The zombies' behaviour was no longer down to the supernatural. They were among us," says Mark.

Shaun of the Dead was an affectionate spoof of the zombie genre and both Mark and Dominic enjoyed the 2004 rom zom com.' "It was great, arguably the greatest British zombie movie," says Dominic. "It reintroduced a sense of hero worship. That same year saw a good re-make of (Romero's 1978 gore-fest) Dawn of the Dead, setting in motion a new confidence in the genre. Film-makers aren't afraid to treat it with seriousness and bigger budgets."

  • The Leeds Zombie Film Festival is at the City Varieties Music Hall, Leeds, on Sunday, April 20, from 12 noon until midnight. For tickets ring 08456 441881. For more information visit leedszombiefilmfestival.com