British Prime Minister David Cameron is embarking on a series of visits to Spain, France, and Germany in a bid to sell his idea of reforming the EU to other leaders, it was confirmed here on Monday. Cameron will meet Spanish Prime Minister Mariano Rajoy in Madrid before heading to Paris, Downing Street officials said. The premier believes the EU needs to change to allow Britain, or other member states, not to be bound by all its decisions. Ahead of the talks, he told European newspapers support for EU membership was now "wafer-thin" in the UK. Cameron has argued a new settlement is needed before UK voters are asked if they want to end ties with Brussels. In his keynote speech on Britain's future in Europe earlier this year, the prime minister pledged to hold an in-out referendum during the early part of the next parliament - by the end of 2017 at the latest - if the Conservatives win the next general election. Cameron will make his first official visit to Madrid for bilateral talks with Rajoy today, before travelling to Paris for a working dinner with French President Francois Hollande. He will meet German Chancellor Angela Merkel later this week. The UK prime minister is facing resistance from France and Germany over his plans to create fresh EU agreements, and media here understandably said this would be an important week of diplomacy for Cameron. Meanwhile commentators said if Cameron would achieve his goal of a more flexible European Union, in which some countries, and in particular non-eurozone members like Britain, can opt-out of certain European laws and directives, he'll have to win-over these key European players. However, the priority right now, for Germany, France, and Spain is how to fix the economic crisis within the eurozone, they noted. Ahead of his European visit, Cameron told reporters three treaties had been put forward since he took the keys to No 10. "So I'm sure there will be treaty change," he added. "I'm absolutely convinced that there will be the need to reopen at some stage these treaties, not least to solve the problem of the eurozone. "The eurozone in my view needs to have further treaty change, and just as eurozone countries will argue that it's necessary to have treaty change, I think it's perfectly legitimate to argue that non-eurozone countries might need to have treaty changes that suit them." In joint interviews with five European newspapers, Cameron said the EU had "sometimes overreached itself with directives and interventions and interference." He said the best outcome for Britain would be "membership of a reformed European Union", while arguing the case for a "more flexible Europe". "Britain is not in the single currency; neither are many other countries. You know, some countries want to go ahead with the financial transaction tax. We don't," he said. "I think we can have a flexible Europe where we don't all have to do the same things in the same way at the same time." In his interview, Cameron stressed it was important to respond to falling support for the EU in Britain. "The two themes of my speech are first that Europe needs reform. But the second is that we need to recognise that consent for Britain's membership of the EU and all the ways that it's changed has become wafer-thin in Britain.