Show Hide image World 27 August 2014 Ukip still claim Labour will promise an EU referendum - but what if they're wrong? Farage needs to explain why he could prevent the referendum he has always wanted. Print HTML Ukip may no longer be a single-issue party, but it still has a defining cause: the withdrawal of Britain from the European Union. Twenty years after it was founded, David Cameron finally gave the party what it wanted last year: a promise of an in/out referendum. The PM’s pledge created an awkward question for Nigel Farage: why, if you want a vote so badly, are you helping to stop the Tories (who have promised one), rather than Labour (who haven’t), winning the general election? As is well known, despite Farage’s protestations to the contrary, Ukip draws nearly half of its support from 2010 Conservative voters. The divided right, combined with a more unified left, could gift Ed Miliband the keys to Downing Street. To this, Farage had a simple reply: after the European elections, and Ukip’s victory, Labour, too, would be forced to promise a referendum. He said in April: "The way to get a referendum on Europe is to beat Labour in May and force Ed Miliband to promise a vote on Europe if he becomes Prime Minister. If both the big parties promise a referendum, we should get one. That's why all our concentration is on Labour in the next few weeks." The elections came, and Ukip triumphed, but Miliband did not waver. Rather than matching Cameron’s pledge (as some on his own side demanded), he maintained that a Labour government would only hold a referendum in the unlikely event of a further transfer of powers to Brussels. Miliband, who rightly believes that he has a good chance of becoming prime minister, is not prepared to allow the opening years of his premiership to be dominated by a vote that he would struggle to win, and that could force his resignation. For a guaranteed referendum, the public will have to back the Tories. So what does Ukip say now? When I asked a spokesman earlier today, I was told: Labour have a near blank manifesto, and as the general election fast approaches, we expect their stance on the EU will change as their hopes of an overall majority continue to fall apart. Just like the Conservatives they are haemorrhaging votes to Ukip. The wise decision would therefore surely be to offer a referendum. In fact, as I’ve argued before, there are many more reasons for Labour not to offer one, but leave that aside; the question Ukip must answer is: "what if you’re wrong?" Unlike Cameron, Miliband does not lurch, he does not U-turn. When a stance is adopted, typically in the form of a detailed speech, it is maintained. With Labour far more united than the Tories on Europe (a reversal of the situation in 1975), there is no prospect of Miliband coming under comparable internal pressure to Cameron. The answer to that question was provided in the second half of the spokesman’s response: "The only reason the Tories are even discussing a referendum is due the threat of Ukip. However nobody else can be trusted on this issue. Both coalition partners went into the election promising a referendum, yet when the government came together the Lib Dems blamed the small print of their leaflet for withdrawing the offer and Cameron showed that his cast-iron guarantee was also just hot air. The only way to get anything other than an empty promise on the EU is to vote Ukip." Based on Cameron’s past failure to deliver a referendum on the Lisbon Treaty (after it was approved by EU member states before the Tories entered office in 2010), Ukip argue that he can’t be trusted this time round. It is precisely to counter such claims that Cameron has vowed to resign as prime minister if he is unable to deliver a vote on EU membership. Such is the (understandable) cynicism of the electorate, that even this may not be enough. But as the general election approaches, there are at least some Ukip voters who will ask why the party is scuppering their chance to have their say in 2017. If he is to retain their support, Farage needs to come up with a better answer soon. › During an unexpected boom in the industry, David Cameron is fumbling on slavery George Eaton is political editor of the New Statesman. Subscribe More Related articles Peter Mandelson: I pray every day for an early election to end Labour's awful state Jeremy Corbyn to tell members: "Prepare for a 2017 general election" What will Labour's new awkward squad do next?