William Hague has said Douglas Carswell's decision to defect to Ukip is "totally counter-productive" because only the Conservatives can offer the public a choice on EU membership.
The Leader of the Commons said: "It's a totally counterproductive thing to do, of course, because the only chance of real change in Europe, the only chance of having a referendum where people can decide to say in the EU or leave the EU is having a Conservative government."
Backbench Tory MP Mark Pritchard agreed with Mr Hague, saying Mr Carswell had made an "error of judgment" that would end up helping Labour in the 2015 general election.
More top news
New research has found #Brexit was the most commonly occurring hashtag for abusive tweets.
Leader Paul Nuttall said: "We cannot be cowed or allow our way of life to be undermined by those who wish to do us harm."
Ouarzazate in Moroco is all about the movies and half the city's residents work in showbusiness.