The former Home Office minister's popularity has been on the rise since she saved the nation from the spectre of Michael Howard as Tory party leader by remarking that there was "something of the night" about him. She gave a barnstorming performance at last year's Conservative Party conference and has become a darling of the Tory press.
Her first novel, The Clematis Tree, explores the strains placed on the family of a profoundly handicapped child by the passage of a Euthanasia Bill. Ms Widdecombe, who converted to Catholicism, is fiercely opposed to euthanasia.
She is working on a second novel, set in wartime France.
Yesterday she said that she was immensely excited by the publishing deal.
"There was a certain amount of scepticism around when I said I was writing it but I have had it in my head for a long time and I had confidence in it," she said.
"Nevertheless I was relieved when it was accepted straight away. I was afraid they would think I was a politician dabbling in writing rather than a serious writer."
Ion Trewin, who accepted the novel for the publishers, said: "This is a wonderful novel and opens up a whole new career. It is hard to believe it is a first novel. It reads as though she has been writing all her life."
Martyn Goff, critic and administrator of the Booker Prize, was more sceptical.
"The chances of the publisher getting their money back are very low," he said. "It is more to do with her name recognition, although obviously there is a chance she's written something wonderful. But more likely it's part of the trend of paying out huge advances for those with notoriety or fame."