The polymath, who turned 80 at the end of last year, is still in intensive care after suffering serious back, head and leg injuries almost two months ago.
Organisers say they are “devastated” that Gray will be unable to appear after spending years trying to get him to speak about his iconic novel Lanark. He finally relented after the Edinburgh International Festival commissioned a new stage adaptation of the book, which gets its world premiere later this month.
Gray, one of the biggest draws at the book festival in recent years, had also been involved in early discussions with the creative team behind the stage production, and may even have narrated part of the show.
Gray was discovered by a neighbour in the early hours of the morning lying outside his flat in Glasgow’s west end after apparently falling down a flight of stairs. His condition is said to have been “extremely critical” at times since the accident. His son Andrew, sister Mora and other family members have been maintaining a bedside vigil.
Gray’s agent, Sorcha Dallas, said it had initially seemed that the artist would “recover pretty quickly, all things considered.”
But she added: “Almost eight weeks later, Alasdair still remains in intensive care. His condition has been at times extremely critical, but there has been a slight improvement over the last week so we remain hopeful that this will continue.
“Andrew has been over for the last seven weeks, putting his life on hold in America to care for his father, supported by Alasdair’s sister Mora and her daughters. He has a lot of love and support around him and the outpouring of support and hope for his recovery has been very moving.”
Leading Scottish playwright David Greig is adapting Gray’s 1982 masterwork which was written over almost 30 years. Ms Dallas added: “We hope he will, in time, watch a recording of the production and read the reviews of what I’m sure will be an inspiring and sensitive adaptation.”
Book festival director Nick Barley said: “We were obviously devastated to hear about the accident.
“I immediately sent a card and book by one of our authors, Theodore Zeldin’s The Hidden Pleasures of Life. Naturally, he was keen not to cancel.
“Even though people would have heard he was unwell, his event was within a whisker of a sell-out. We didn’t cancel the event, even though he was quite badly injured, and he was very much hoping to be well, but we all realised it was unsise of him to even consider coming.
“Having spent years trying to persuade him to talk about Lanark, I was devastated, but I’m very much looking forward to welcoming him when he is well again.”