Conservative MP Mark Pritchard has revealed he "seriously considered" defecting to Ukip last year, as the Tories struggled to deal with the surge in support for Nigel Farage's eurosceptic party.
On Thursday, Tory defector Douglas Carswell became Ukip's first ever elected MP by cruising home to victory at the Clacton by-election. Ukip also also stunned Westminster by coming within 617 votes of snatching the safe Labour seat of Heywood and Middleton.
Carswell's victory, and the prospect of fellow defector Mark Reckless winning the Rochester by-election, is spreading fear throughout the Tory benches. The party is also worried that a Reckless win will encourage other Conservative MPs to jump ship.
Speaking to the BBC's Daily Politics programme on Friday, Pritchard, an arch-eurosceptic, admitted he had once been tempted. "I am not going to defect to Ukip," he said. "There was a time when I seriously considered it."
Pritchard said it was only when Cameron promised in January 2013 to hold an in/out referendum that he decided to remain as a Conservative MP. "I had considered it. Now we have that commitment, clearly it makes sense to make the [anti-EU] case as a Conservative MP," he said.
Asked by Sky News whether he expected more Tory MPs to defect, Carswell said what was important was how many voters were going to switch. "We need to stop obsessing about how many people in Westminster are going to make the change," he said.