The Lord of the Rings is the only real contender in "a one horse race" to win the BBC's Big Read contest, according to bookmaker Ladbrokes.
The release of the last Lord of the Rings film could influence voting
Ladbrokes has closed betting because, in the last week, the only money laid has been for the JRR Tolkien classic to win the competition's public vote.
But the BBC said the competition was far from over and viewers should vote to "make a difference".
The contest lets viewers vote for their favourite from a list of 21 novels.
A Ladbrokes spokesman said: "Nobody wants to back anybody other than Tolkien - even the Harry Potter money has dried up.
"We cannot continue betting on a one horse race. We will open the market again if we believe that The Big Read is a contest."
FINAL BIG READ ODDS
1/3 - The Lord of the Rings
5/1 - Pride and Prejudice
5/1 - Harry Potter and the Goblet of Fire
10/1 - Great Expectations
10/1 - Rebecca
When the shortlist of 21 was first announced, there were a range of bets on The Lord of the Rings, Harry Potter and Pride and Prejudice, he said.
But since then, Tolkien has become the "red-hot odds-on favourite" and other bets dried up.
The hype surrounding the final Lord of the Rings film, due to be released on 17 December, could also influence voting, the Ladbrokes spokesman said.
The Big Read winner will be revealed on 13 December, after seven weeks of television pleas by celebrities to win votes for their favourite book.
In a statement, the BBC said the race to find Britain's favourite book had "only just begun" and thousands of votes for titles across top 21 were flooding in.
"Only three books have been championed on television up until now and the contest is far from over, with titles moving around the leaderboard day-by-day," it said.
"We would urge viewers to vote for their favourite and make a difference."
On BBC Two on Saturday, Ruby Wax will put the case for Catcher in the Rye, Phill Jupitus for Winnie the Pooh and Clare Short for Captain Corelli's Mandolin.
The contest has come in for criticism from some authors, with Andrew O'Hagan accusing it of being "anti-literary" and Adam Mars-Jones calling the show "obscene".