Dickens purists should look away now - David Nicholls has revealed that he has written an alternative ending for his forthcoming adaptation of Great Expectations.

Screenwriter David Nicholls, who is adapting the latest feature version of Great Expectations for the big screen (directed by Mike Newell and starring Ralph Fiennes and Helena Bonham Carter) revealed rather bravely today that he has “come up with an ending that isn’t in the book.”

“Dickens came up with two endings, one which is incredibly bleak and one which is unrealistcally romantic and sentimental. Neither are quite satisfactory and we’ve tried to read a middle path. It’s somewhere in between. It draws on events in the book and takes them in a slightly different direction,” admitted Nicholls at the launch of the BFI’s Dickens on Screen retrospective which runs January-March 2012 as part of a year long celebration to mark the 200th anniversary of the author’s birth.

“But it’s in no way sacrilegious,” laughed Nicholls, responding to the audible gasps in the room. “It’s a very faithful adaptation, but in our film you do see things that you haven’t seen in previous versions.”

Nicholls, who revealed that Great Expectations is his favourite book, said that he has also drawn on the “film noir” genre for his “thriller” adaptation, comparing the last act of Great Expectations to the end of Chinatown. “It is this wonderful unravelling of beautiful intricate plot. There is a femme fatale in Estella, the crimes carried out on children in the past have a legacy on the present day.”

And it gets darker, as Nicholls explained that when Pip visits Miss Havisham, it’s “a bit like going to see Hannibal Lector.”

Nicholls admits that he is “extremely excited and a little daunted” to be working on the new film, which is currently shooting in the UK, especially as there were “two very strong reasons not to get involved. Great Expectations is a near perfect work of art and it has been made rather well by David Lean into a film that many people consider to be the greatest British film.”

“The David Lean film will always be a masterpiece and ours will be different. Watching it again there were elements that weren’t fully explored and we will be trying to explore those in our version,” added Nicholls, who was joined at the lunchtime event by Sir Derek Jacobi (who appeared in the feature version of Little Dorrit).

The three month retrospective, which has been co-curated by Adrian Wootton and Michael Eaton, will feature rarely seen silent work from the 20th century such as Scrooge - or Marley’s Ghost (1901)and David Copperfield (1913) alongside Hollywood interpretations inlcuding The Only Way (1926) and A Tale Of Two Cities (1958)starring Dirk Bogarde. As well as, of course, David Lean’s Great Expectations and Oliver Twist.

Meanwhile Film London’s CEO Adrian Wootton revealed that the new feature version of Great Expectations should be ready for next autumn - just in time for the next London Film Festival.