David Cameron has come a long way on Europe. As a candidate for the Conservative leadership a decade ago, his message was that his party must stop “banging on about the EU” because the Eurosceptics had become the national equivalent of the saloon bar bore complaining that the country is going to the dogs. The Tories, he suggested, should get with it and talk instead about general wellbeing, trees and the inadvisability of melting the Arctic. Take off your tie, daddio: only boring old squares worry about ever-closer European Union (EU) and qualified majority voting. How times change. Ten years later, it is Cameron touring the continent banging on about Europe ahead of an in-out referendum that, short of an economic disaster, will dominate the early years of this parliament. What happened?

In part, the answer is the rise of Ukip, which for a time terrified the life out of the Conservatives before Nigel Farage’s party failed at the recent general election by only quadrupling its vote to 3.8 million souls. But contrary to the claims of Europhiles, who say a referendum is unnecessary, what really changed everything was the eurozone meltdown from 2010, when the continent was plunged into a long-running debt crisis that mutated into an existential crisis. The old model, in which those inside the single currency and those outside pretended to voters that they were going in roughly the same direction, was bust and a new dispensation was clearly required. In such circumstances, with Europe changing, the pressure for the first British vote on the subject since 1975 was always going to be overwhelming. Before Britain can move on, once and for all we will have to make our minds up. Are we in and going to get on with it, albeit in a reformed EU? Or will we stop grumbling and try the alternative outside?

At first, Cameron — ever the essay crisis leader — put off dealing with the long-term consequences of the Eurozone emergency. In the early years of the last parliament, when he and his ministers might have been undertaking the groundwork for a redesign of the European Union, to create a two-speed EU, he refused to be hurried. Following fights with the EU on budgets, and sustained pressure from Conservative backbenchers, convinced that the moment was approaching where Britain must choose, the Prime Minister eventually and sensibly adopted the policy of a renegotiation to be followed by a referendum. The Chancellor of Exchequer George Osborne was instrumental in getting him to that position. Now, here comes the fabled great renegotiation, which opened last week with the Prime Minister undertaking a difficult European tour, rescued by the German Chancellor, Angela Merkel, saying that it might be possible to change the EU’s treaties to accommodate British demands.

Yet, as Cameron shuttled about, having breakfast, lunch and dinner in different capitals, it was difficult to avoid the awkward thought that so far he does not seem to be asking for very much. What, exactly, are his “red lines” that we keep hearing so much about but which never seem to materialise? Be patient, says the Prime Minister. The red lines are being inked out by officials, and an announcement of the package of proposed reforms is pending. Just as in the election, critics should wait for the result before judging the outcome, he says. Top of the No 10 Downing Street list seems to be a reasonable restriction on benefits for migrants from within the EU, although if Britain chose to implement such measures unilaterally the sky would not fall.

While there would be a rumpus, of course, and legal action, the EU would survive. But there must surely be more to this renegotiation than rules on benefits. It cannot be that a historic tussle to decide the future direction of the great continent of Europe is going to come down to a row about child benefit going to the offspring of hardworking Polish plumbers, can it? Beyond that, it seems that the Prime Minister wants treaty change to end the understanding that all member states are signed up for ever closer union. Fine, but what in practice will that amount to by the time of the referendum? Even moderate Eurosceptics are looking for more than a guarantee that the UK will not endure greater integration, when so much of it has happened already. The repatriation of existing powers and a looser relationship should be the aim.

A government serious about delivering such reforms should at least be looking to scrap anti-competitive social and employment laws that come from Brussels and trying to win new flexibility for the UK to do its own trade deals. Right now, the Prime Minister has numerous advantages that mean he may get a successful outcome on his terms - a vote to remain in an EU with minimal changes — if enough voters decide to back what he recommends or conclude that rows about Europe do not matter much. He is an election winner; the economy seems to be doing well, for now; he has considerable leeway with his relieved and grateful party; and he has vanquished those who thought that Britain this month would be at the beginning of a messy experiment with Tory minority government.

However, even election winners can run into trouble within months of a victory. Just ask Sir John Major, the surprise election winner in 1992, who by the autumn of that year was left surveying the ruins of his premiership when Britain was evicted from the European Exchange Rate Mechanism. Cameron is in a much stronger position. But if his red lines are not forthcoming, sharpish, and if what he produces are merely pinkish daubs painted by the Foreign Office, the suspicion will grow that the government is engaged in perpetrating a fraud on the public and attempting a rerun of slippery Harold Wilson’s meaningless renegotiation four decades ago.

Such an outcome would risk boosting Better Off Out by driving moderates into that camp and it would gift Out, behind in the polls, a way back into the race. In an age of scepticism about elites, and populist anger about Establishment deceit, the Outers would love to be able to say during the campaign that Cameron’s vaunted red lines are a stitch-up.

— The Telegraph Group Limited, London, 2015