The winner will be formally announced on July 10, as part of the London Literature Festival at the Southbank Centre in London but bookmakers have now closed betting on the award after Rushdie's Midnight Children emerged as the clear favourite.
"The voting pattern has been well established now and will not change," a senior executive of William Hill told PTI on Thursday.
Public voting for the award is officially open till July 8 but bookmakers William Hill have 'closed the book' and have stopped accepting bets.
Rushdie was the firm favourite at 6/4.
Rushdie was knighted by Queen Elizabeth II in June for his "services to literature."
Rushdie who has written a number of acclaimed books, went into hiding in 1989 after the publication of his controversial book, The Satanic Verses. The novel sparked widespread protests by Muslims and Iranian leader Ayatollah Khomeini issued a 'fatwa' against him, saying the book was a blasphemy against Islam and sentenced him to death.
Besides Rushdie, the other five contenders are: Pat Parkers (The Ghost Road), Peter Careys (Oscar and Lucinda), J M Coetzees (Disgrace), J G Farrells (The Siege of Krishnapur) and Nadine Gordimers (The Conservationist).