The Conservative Party MP most likely to defect to Ukip before Christmas was at school with Nigel Farage, according to Ladbrokes.
The bookmaker has put Kettering MP Philip Hollobone as the most likely Conservative MP to jump ship at 2/1. Hollobone had a 9,000 majority over Labour at the 2010 genral election.
Hollobone and Farage were both pupils at Dulwich College, a prestigious private school for boys in southeast London costing £15,000 a year.
The Eurosceptic 50-year-old has been one of the Coalition Government's most rebellious MPs.
Hollobone went against Prime Minister in the House of Commons 129 times between May 2010 and May 2013, according to University of Nottingham academics Philip Cowley and Mark Stuart.
In comparison, the researchers revealed that the most rebellious Liberal Democrat MPs at the time (Andrew George and Mike Hancock) only voted against the government 44 times over the same period.
But Hollobone ruled out defecting to Ukip earlier in the year and stressed that he supported David Cameron's promise to offer voters a referendum on the UK's membership of the European Union (EU) in 2017 if he gains power after the 2015 General Election next may.
"I am not defecting to Ukip," Hollobone told the Northamptonshire Telegraph in September.
"I believe that we need a referendum on Britain's membership of the EU and should we ever get that referendum I shall be voting for Britain to leave the EU so that we can get back control over our borders once again."
The Conservative MP caused controversy in 2010 after proposing a law to ban wearing burkas and balaclavas in public.
But the Face Coverings (Regulation) Bill failed to even get a second reading the House of Commons.
The update from Ladbrokes comes just days before the Rochester and Strood by-election, where Conservative defector and Ukip candidate Mark Reckless is tipped to win.
"The Rochester by-election is now a one-horse race and the only question in punter's minds is who's next," said Matthew Shaddick, a sportsbook manager at Ladbrokes.
Hollobone had not responded to a request for comment at the time of publication.