Claire Tomalin is beating husband Michael Frayn in bookmakers odds to win the Whitbread prize, as the couple compete against each for the prestigious award.

The husband and wife authors, vying against each other for the Whitbread book prize, believe they are in a no-win situation because they will be upset if one of them loses.

Tomalin is currently in the lead with odds of 2.5 to one for her book Samuel Pepys: The Unequalled Self, from betting firm William Hill.

Her husband's book, Spies, currently has odds of 3.5 to one.

Frayn and Tomalin, both 69, won the Whitbread novel and biography prizes respectively, pitting them against three other authors for the �25,000 overall prize, which will be announced on 28 January.

There are three other shortlisted authors: Paul Farley, for his poetry collection The Ice Age; Norman Lebrecht for his novel The Song of Names; and Hilary McKay for her children's book Saffy's Angel.

Lebrecht's odds are 4.5 to one, Farley's five to one and Mackay's seven to one.

Whitbread winners

Novel: Michael Frayn, Spies First novel: Norman Lebrecht, The Song of Names Poetry: Paul Farley, The Ice Age Biography: Claire Tomalin, Pepys: The Unequalled Self Children's Book: Hilary McKay, Saffy's Angel

Frayn won the novel award with his wartime coming-of-age book Spies, described by judges as "subtle and beautifully rendered".

Tomalin's biography of Samuel Pepys won the judges' vote in biography category.

All the attention for the prize now focuses on the couple, who are tipped as the frontrunners, but Frayn was quick to point out that there are three other contenders.

'Terrific'

"It would be a bit humiliating after all this performance for us both to come back into the twilight again," Frayn told Radio 4's Today programme.

Of the rivalry for the prize, Tomalin said there was "no happy solution" if one should win over the other.

"If I win I would so upset that Michael had not won because I think Spies is a terrific, and I think I can say Michael would be upset if he won and I didn't ," she said.

Although they write separately, with Michael working from a flat near their London home, they are both supportive of each other's work, giving criticism and advice, but admit it is not always taken.

Tomalin said their nomination was also a "triumph for the oldies" because so many young authors have been receiving attention.

Poet Paul Farley is another winner

Spies follows two boys who grow up in a suburban cul-de-sac, one of whom discovers his mother is a German spy.

Frayn is also known as a playwright, acclaimed for works including Noises Off and Copenhagen.

Tomalin took the biography award for Samuel Pepys: The Unequalled Self, which was lauded by judges as a "superb, humane and compassionate portrait".

Paul Farley won the best poetry award for his collection The Ice Age.

Brought up on a sprawling council estate in Liverpool, he spent 13 years as an artist in London before he could "stand the smell of turpentine no longer" and took up poetry instead.

Journalist Norman Lebrecht scooped the best first novel award for The Song of Names, a tale of two boys growing up in wartime London.

Record entries

Lebrecht is better known as a journalist

The assistant editor of the London Evening Standard is better known for his arts writing and his work on TV and radio.

Finally, Hilary McKay won the children's book award for Saffy's Angel, about an adopted girl who has a stone angel bequested to her by her grandfather.

As well as being entered for the main Whitbread prize, each of the five winners gets �5,000.

Private Eye editor Ian Hislop leads the judging panel for the main prize, which includes authors Joanna Trollope, poet Wendy Cope and Sunday Times fiction editor Peter Kemp.

Last year's Whitbread Book of the Year was awarded to Philip Pullman for The Amber Spyglass, the first time that a children's book had been the overall winner.