David Cameron rebukes Cabinet ministers over EU referendum In recent days Tory grandees including Lord Lawson, Lord Lamont and Michael Portillo have all called for Mr Cameron to lead the UK out of the EU. The Prime Minister attacked those former ministers, warning that their desire to "throw in the towel" before negotiations have even started is a "strange opinion." Eurosceptic Tory backbenchers have engineered a Commons vote this week over an EU referendum. The MPs have tabled an amendment criticising the failure of the Queen's Speech to include a bill on a future referendum. Mr Cameron is giving backbenchers a free vote on the issue but has told ministers they should abstain, effectively allowing them to openly disapprove of the Government's legislative agenda in the Commons. The Prime Minister wants to try and renegotiate the UK's relationship with Europe before holding an in/out referendum if the Conservatives win an overall majority at the next election. Speaking while travelling to the United States, Mr Cameron claimed that "every" Conservative Cabinet minister believes that he will be able to claw back powers from Europe. "Every Conservative Cabinet minister is confident that we will be able to deliver those changes," Mr Cameron said. So that's what we are pushing towards. There is only one way to get this in/out referendum and that is to make sure we deliver a Conservative victory in the next election. The Prime Minister added: "What all Conservative Cabinet ministers agree is that we should be spending the next period improving the EU and improving our relations with the EU and then putting that choice to the British public in a referendum. That is our policy, it is the right thing to do and I think we're all confident of our success. However, he attacked Mr Portillo, the former Defence Secretary, who last week called for Mr Cameron to leave the EU and alleged that his promise to hold an in/out referendum is an "insincere ploy." "I have great respect for Michael Portillo, I remember working as his special adviser many years ago," Mr Cameron said. But the point I'd make to these people is you shouldn't give up before a negotiation has started - [that] seems to be an extraordinary way to go about things.  The idea of throwing in the towel before the negotiation has even started I think is a very strange opinion.