FICTIONALISED portraits of living people, such as the widely praised film The Queen, are an outrageous violation of privacy, according to one of Britain’s best-known literary critics.

David Lodge, who wrote an acclaimed biographical novel about the (long-dead) writer Henry James, was one of several authors addressing the increasingly blurred distinction between fact and fiction on the final weekend of The Times Cheltenham Literature Festival.

Delivering the event’s signature lecture on Saturday, Mr Lodge, who has written 12 novels and numerous works of criticism, said that the two genres were probably more intertwined than at any time since the 18th century, when Daniel Defoe turned the broad details of Alexander Selkirk’s years as a castaway into Robinson Crusoe, and Samuel Richardson composed long fictional works from realistic-looking letters.

The drift of novelists into writing biographical novels, or “bionovels”, has had much to do with this, he said, citing his Henry James book Author, Author, Julian Barnes’s Arthur & George, which fictionalised the life of Arthur Conan Doyle, and Michael Cunningham’s The Hours, on Virginia Woolf.

But producing bionovels or biographical films about the living was a step too far, he felt. “I don’t think it’s legitimate with a living person. The big hit in Sweden this year is a biographical novel about Ingmar Bergman, who is still alive. That’s very unusual,” he said.

The Queen, Stephen Frears’s Oscar-tipped film about how the Royal Family responded to the death of Diana, Princess of Wales, should not have been made, he believes. “People in public life are handicapped because they cannot challenge these things without calling down more unwelcome publicity than they are already getting.

“Look at that Blunkett play. (A Very Social Secretary, screened last week on Channel Four.) I would have felt very hurt by it in his position and I felt guilty enjoying it.

“I don’t think the same issues arise with dead people. In the last decade or so the biographical novel has become a fashionable format for literary fiction. It is sometimes seen as a sign of exhaustion (with the novel and biography) . . . but, in exploiting the power of facts, it is returning to the 18th-century tradition.”

Going farther back, writers and audiences were not particularly concerned by historical accuracy because they had no resources to verify it, he added. “The bionovel . . . complements biography and can give readers a more vivid sense of what it was like to be X or Y at particular moments in their lives.”

Explore Books

• Book Extracts

• Book Reviews

• Books Group

• Audio Books

Times Recommends

• The 100 Best Books of the Decade
• The Times picks the 50 best paperbacks of 2009
• The conversation: James Ellroy