Conservative grandee John Redwood has dismissed the "so-called" eight Tory MPs allegedly considering defection to Ukip as "figments of Ukip's imagination".
"Dream on Ukip," the eurosceptic MP for Wokingham and former Wales Secretary told Radio 4's Today programme.
"I treasure the words of Mr Carswell which he was speaking yesterday. He said that we need to deliver an in-out referendum, he said it would only happen if David Cameron was prime minister," Mr Redwood said.
"He said we must do nothing to make the prospect of a referendum less likely. He was super-loyal until yesterday."
More top news
Heavy showers set to spread into western areas tomorrow.
Andy Murray is Britain's last hope of a 2015 Wimbledon win after overcoming an apparent shoulder injury to beat Italy's Andreas Seppi.
New Tour de France time-trial record set after Australian Rohan Dennis raced into the lead during Stage one of the competition.