David Cameron says he can win yes vote in EU poll DAVID Cameron has sought to reassure business leaders that he can secure a yes vote in a promised referendum on Britain's membership of the European Union. The Prime Minister, addressing the CBI conference in London, said he was confident he could secure support for the UK to stay in the EU in the vote which the Conservatives have said they will hold if they win the next general election in 2015. The CBI published research which it said showed that it was "overwhelmingly" in Britain's ­interest to remain in the EU, with membership worth between £62 billion and £78bn, about 4-5 per cent of the country's total economic output. During a question and answer session with business leaders, the Prime Minister insisted his plan to re-negotiate the terms of Britain's membership and then put the new settlement to a referendum before the end of 2017 was not a "short-term tactical ploy." He acknowledged that ministers had not done enough to make the case for the EU but said that he believed the case for a yes would be strengthened once reform had been achieved. He said: "I think that will be a much easier argument to win than the argument we would have if we had an in/out referendum today. I sit round that European Union table... and I can see this organisation is going to change. It is changing in front of our eyes because of the euro. Those countries that are in the euro, they need change to happen. We shouldn't stand in their way. But I think it is perfectly legitimate to say, "You, the ­eurozone members need these changes. Well, we outside the euro, we need some changes too. I think it will be a much more balanced debate because we won't be arguing in/out on the status quo, we'll be arguing about staying in a reformed ­European Union with a better deal for Britain. With the backing of organisations like this one and business voices about the importance of staying in a reformed European Union, I think it is an argument we can win. Director general John Cridland said: "We have looked beyond the political rhetoric to examine the pros and cons of EU membership and British business is unequivocal - the single market is fundamental to our future." Shadow chancellor Ed Balls said that leaving the EU would be "reckless, foolish and deeply damaging" for Britain."