Ukip defectors "reckless Reckless" and "kamikaze Carswell" risk helping Labour leader Ed Miliband into Number 10, a senior eurosceptic Conservative has warned.
Former Tory deputy chairman Bernard Jenkin insisted ex-MPs Douglas Carswell and Mark Reckless were impatient and had "kicked the table over" by deciding to join Nigel Farage's Ukip.
The Harwich and North Essex MP also called on Prime Minister David Cameron to unite the Tories and the country by clearly outlining the party's approach to the European Union, including what it wants from its relationship with the EU if renegotiation fails, in the 2015 general election manifesto.
Fellow eurosceptic Tory backbencher Sir William Cash also said he was "so disappointed" with Carswell and Reckless for leaving the party, adding Ukip deprives the Conservatives from securing marginal seats and therefore obstructs change being delivered on the EU.
Speaking at a fringe meeting at the party's conference in Birmingham, Jenkin noted fellow panellist MEP David Campbell Bannerman left the Tories to join Ukip but returned as he realised the Tories are the only vehicle in British politics that can "win this argument" on behalf of the British people.
He said: "If the Conservative Party is lost then the country is lost and I suppose that's what really distinguishes us between reckless Reckless and kamikaze Carswell and I choose my words carefully.
"These are people who, I think, have arrived only quite recently into this debate. They are impatient with those of us who have been making arguments for much longer than them. They think they know much better than us and they kicked the table over and decided to go and join Ukip with only one effect - that they would be helping Ed Miliband into Number 10 rather than helping to win the argument about the European Union within the Conservative Party.
"After all, it's within the Conservative Party that we have been winning the argument."
Turning to the need for EU questions to be answered in the Tory manifesto, Jenkin said: "We are in a strong position, we have principle on our side, we have the national interest on our side and these are things that must be spelt out in our manifesto if we are to unite our party and unite our country behind a majority Conservative Party at the next general election."
Stone MP Sir William told delegates: "I am so disappointed with Douglas and I am so disappointed with Mark for this reason - it is simply not possible for the agenda that we as a Conservative Party have provided in changing the nature of the European argument in this country, it is impossible without changing the laws, you have to have a majority in the House of Commons.
"That's the way to change the European Communities Act, that is the way to get this balance right, that is the way to retrieve our sovereignty and sustain our democracy, that's what we need and Ukip... even if they had a reasonable number (of MPs), even if they make a breakthrough in the general election, which I doubt, by depriving the Conservative Party of the marginal seats it is actually stopping, obstructing, impeding, preventing, destroying, undermining a capacity of the Conservative Party to deliver the kind of changes that I've outlined that are so important."Suggest a correction