Sting in the tale for book publisher as Jennie turns out to be Charles

But when they tracked her down to buy the rights to the book, they discovered that would be impossible. For the prize is for women - and Walker is really Charles Boyle and quite clearly a man.

Boyle, 57, from Shepherd's Bush, published the book himself after receiving a rejection letter the same day as he inherited £2,000 from an uncle.

Although the novel is written in a woman's voice in the first person, he took a female name as author on a whim.

"It wasn't premeditated," he said. "If I'd actually realised that this book was going to get the attention that properly published books get, I would have worried more because it's a form of deception whereas the way I did it was pure selfindulgent fun."

It was a review that triggered the interest of publishers. Nicholas Lezard in the Guardian described 24 For 3 as "a little marvel of a novella".

He wrote: "It's funny, clever, illuminating, deeply kind-hearted and doesn't outstay its welcome. It's not self-indulgent, things happen in it, surprising things, like in an old-fashioned novel, yet it's perfectly contemporary and every word has been chosen with subtle care."

Boyle said: "It was the kind of review authors kill for."

The telephone soon began ringing with people wanting to talk to Jennie Walker.

After meeting the staff from Bloomsbury, he told them: "You have."

Their surprise was echoed at the Society of Author awards in London this week. Many initially assumed Boyle must be Walker's agent when he walked up to accept the £4,000 McMitterick Prize for a first novel published by an author over 40. Boyle, who used to work for Faber & Faber, is best known as a minor poet once shortlisted for the TS Eliot Prize and Whitbread Awards. He was last invited to the Society of Authors awards 27 years ago, when he won a Cholmondeley award for poetry.

His book is the story of a woman whose attention is torn between her cricketloving husband, a lover and her 16-year-old missing son.

Until now, it has sold just over 500 copies in independent bookshops and online. A new edition is being put out by Bloomsbury, the Harry Potter publishers, in August.

Publisher Helen Garnons-Williams said all the middle-aged women in the office had been convinced the author understood them - unaware it was a man. She added: "They all loved it. They said, 'She just gets inside our head.' We thought it would be a contender for the Orange Prize."

Now they are consoling themselves it might simply be a bestseller instead.