'Harry Potter for adults' is the Booker Prize's dark horse

Surprise 800-page candidate is yet to be published in UK but is one of the novels forcing out the big names

A tale of sorcery and adventure, described as a "Harry Potter for adults", is emerging as a surprise contender for inclusion on the Booker Prize shortlist, due to be announced this week.

A tale of sorcery and adventure, described as a "Harry Potter for adults", is emerging as a surprise contender for inclusion on the Booker Prize shortlist, due to be announced this week.

Jonathan Strange & Mr Norrell, an 800-page debut novel by Susanna Clarke, has yet to be published in the UK. But it has become an instant success in the US and is already drawing attention from Hollywood producers.

Few had heard of Clarke before she was named on the 22-strong "longlist" last month, one of six first-time British writers in contention for the £50,000 award, Britain's best-known literary prize.

Their nomination at the expense of established names has prompted growing criticism about the way the list has been compiled. David Lodge, V S Naipaul, Louis de Bernières and Jonathan Coe have all been ignored, even though they had new books that made them eligible.

Critics, including a number of publishers and booksellers, say the nature of the prize has changed. The prize - whose previous winners have included Salman Rushdie, Margaret Atwood, Iris Murdoch and A S Byatt - no longer seeks the best novel of the past year, they claim, but rewards unusual, experimental tales or gives a break to first-timers.

One, speaking anonymously, said: "There's a feeling that the Booker wants to be more cool and sexy. In the past two to three years, the judges seemed to revel in choosing books that are not traditional Booker choices." Another said: "It is no longer clear what a Booker book is."

The publishers' main complaint is that they struggle to identify which books to enter, and find themselves guessing what they think will appeal to a judging panel that changes each year.

There is also a growing feeling that publishing a longlist, a practice introduced in 2001, is futile. Inclusion does not translate into sales, only the shortlist has that effect, yet failure to make the list is like a damning review.

One publisher, who did not want to be named, said: "If your book comes out around the time the longlist is published and you are not on it, you are dead in the water. It's like getting the worst review of your life."

The criticism is shared by Martyn Goff, the prize administrator, who said that the longlist should be kept secret. But he defended the choices of this year's judges and denied there was any wilful attempt to look for more obscure names.

"There are half a dozen major writers who have not been put on the list, but they were discussed at length. There was a feeling they were not quite good enough," he said.

This year, Alan Hollinghurst's The Line of Beauty, David Mitchell's Cloud Atlas and Colm Tóibín's The Master are thought to be certainties for the shortlist, to be announced on Tuesday.

Clarke's tale is a 12-1 shot to take the prize on 19 October. She spent 10 years on the book, which stitches magical influences into 19th-century historical events. It is in the New York Times bestseller list's top 10 within two weeks of its US publication.

Interest has led to approaches from US producers, although no deals have yet been struck.

David Lodge, 69, emeritus professor of English at the University of Birmingham, is known for novels including Nice Work and Small World. His writing often reflect his working-class Catholic background and life in the world of academia. He won the Whitbread Book of the Year prize in 1980 for How Far Can You Go?

Louis de Bernières, 49, found international acclaim and an international audience for his breakthrough novel Captain Corelli's Mandolin, which was turned into a movie starring Nicolas Cage. His early career included spells landscape gardening and teaching English in Colombia, which have inspired several of his other novels.

Jonathan Coe, 43, made his name with What a Carve Up in 1994, a tale of 1980s greed, and found further acclaim with The House of Sleep. His novel The Rotter's Club, about growing up in the 1970s, is being adapted by the BBC for a three-part drama.

V S Naipaul, 72, a Nobel Prize for Literature laureate, first achieved fame with his novel A House for Mr Biswas, portraying one man's search for autonomy in post-colonial Trinidad, his birthplace. His other books include The Loss of El Dorado and In a Free State. He was knighted in 1990.

FOUR TO WATCH

Cloud Atlas, by David Mitchell (Sceptre)

Mitchell's third novel is more mind-boggling than his last, 2001's Booker-shortlisted Number9Dream. It features six interlocking narratives that run from the 19th century to the far future and back again. It's gloriously inventive and dazzlingly virtuosic.

The Line of Beauty, by Alan Hollinghurst (Picador)

Brideshead Revisited gets an Eighties makeover. Nick, a lower-middle-class graduate, attaches himself to the family of a wealthy Tory MP after falling in love with his son at college. One minute dancing with Margaret Thatcher at a party, the next cruising for men at Hampstead ponds, he is the perfect mouthpiece for an elegant satire.

Havoc in its Third Year, by Ronan Bennett (Bloomsbury)

Historical fiction at its peak: the Puritans have tightened their grip on the land, but in a pocket of northern England some still secretly cling to their Catholic faith. The honest but flawed recusant John Brigge becomes the focus of suspicion in a taut, Crucible-style fable of human weakness and malice.

Clear, by Nicola Barker (4th Estate)

David Blaine is suspended in a box near Tower Bridge. Two misfits who have come to gawp pursue an edgy and one-sided romance while discussing footwear, Westerns, Kafka and Dizzee Rascal. Hilarious, witty and absolutely of the moment.

Suzi Feay, Literary Editor