Lord Lawson Calls For Britain To Leave EU Lord Lawson has become the most senior Tory figure to call for the UK to quit the European Union - pledging to vote 'No' in any referendum on membership In a move that piles further pressure on David Cameron over the issue, the former chancellor warned his proposed renegotiation would only secure "inconsequential" concessions from Brussels. Writing in The Times, he said there was now a "clear" case for withdrawal, insisting the economic benefits would "substantially outweigh the costs," in contrast to the Prime Minister's position. His intervention is sure to further embolden eurosceptic MPs demanding a tougher line to halt the rise of Nigel Farage's rampant anti-EU UK Independence Party (UKIP). Mr Cameron is already under pressure to hold a "mandate referendum" as early as next spring to seek public approval of his strategy of putting a renegotiated settlement to an in/out vote by 2017. In the wake of UKIP's surge in last week's county council elections, there is also pressure to put the strategy to a vote in the Commons in defiance of his Liberal Democrat coalition partners. Lord Lawson, who was Margaret Thatcher's longest-serving chancellor and remains a highly respected figure within the party, said that it was "by no means assured" that Mr Cameron would win the 2015 general election. But he said he believed public demand was such that a referendum would have to happen under Labour in any case. Dismissing the chances of either party securing significant reforms, he said Brussels would fear a "general unravelling" as other countries sought to match the return of powers. "But all this is largely beside the point," he wrote. The heart of the matter is that the very nature of the European Union, and of this country's relationship with it, has fundamentally changed after the coming into being of the European monetary union and the creation of the eurozone, of which - quite rightly - we are not a part. The PM is coming under increasing pressure over Britain's place in the EU That is why, while I voted 'in' in 1975, I shall be voting 'out' in 2017. Not only do our interests increasingly differ from those of the eurozone members but, while never 'at the heart of Europe' (as our political leaders have from time to time foolishly claimed), we are now becoming increasingly marginalised as we are doomed to being consistently outvoted by the eurozone bloc. So the case for exit is clear. But Deputy Prime Minister Nick Clegg told Sky News that Lord Lawson was "completely wrong," and that leaving the EU would "jeopardise" up to three million UK jobs dependent on membership. "I think simply pulling up the drawbridge would be a bad thing for this country that would leave us poorer and less safe," the Lib Dem leader added. Lord Lawson said that while there would be "some economic cost" from leaving the EU single market, in his judgement "the economic gains would substantially outweigh the costs." That would not only be in keeping the UK's £8bn net contribution, but also being removed from excessive bureaucracy, not least the "frenzy of regulatory activism" affecting the banking sector. The foolish and damaging financial transactions tax, imposed against strong UK opposition, is only one example. In part this is motivated by a jealous desire to cut London down to size, in part by well-intentioned ignorance," he said. He added: "Those who claim that to leave the EU would damage the City are the very same as those who in the past confidently predicted, with a classic failure of understanding, that the City would be gravely damaged if the UK failed to adopt the Euro as its currency." A Downing Street spokesman said: "The PM has always been clear: we need a Europe that is more open, more competitive, and more flexible; a Europe that wakes up to the modern world of competition. In short, Europe has to reform. But our continued membership must have the consent of the British people, which is why the PM has set out a clear timetable on this issue.