The pollster changes, but the poll remains the same: Leave is pulling ahead in the referendum vote. The latest shock to the system comes via ICM, in which both their phone and online polling gives Brexit a six-point lead by 53 to 47 per cent. The latest YouGov poll for the Times is starker still: a seven-point lead for Brexit. The mood in the pro-European campaign, already less than sunny, has been driven further into the gloom.

I started the year in a fairly pessimistic position as far as the referendum was concerned, but there are, amid the gnashing of teeth, reasons to believe that the only way isn’t exit.

Out doesn’t “have momentum”. Momentum is a myth

American political journalists are obsessed with the idea that campaigns can build up “momentum”. It’s one of those ideas, like trickle-down economics, that is enduringly popular in sections of the press despite their being little-to-no evidence of its existence in the real world.

The wheeze is that wins lead to wins, that political campaigns or parties can hit form, like an artist or a sports team.

As is often the way with American politics, the idea has crossed the Atlantic, at least as far as Westminster is concerned. As George writes, there is a feeling that “momentum” is now with Out.

There is no evidence – literally none – that momentum is a force in politics. (If you don’t believe me, just Google any of “Hilary Clinton momentum 2008”, “Bernie Sanders momentum 2016” or “Marco Rubio momentum 2016”.

Yes, the polls look good for Brexit – but good polls do not inevitably beget more good polls, let alone good polls. In fact…

The historical trend still favours Remain

Matt Singh, one of the few to call the 2015 election in advance, estimates that to win, the change option in a referendum needs to be leading by more than four points, as the trend is not for one side to have momentum but for voters to revert to the status quo.

Leave’s lead in the rolling poll-of-polls is four points, only just within the danger zone for the Brexiteers, but in the danger zone nonetheless.

Leave’s turnout advantage isn’t all it’s cracked up to be

The baby boomer is one of the few mammals that eats its own young. For the most part, in Western Europe and the States, politicians who are popular among the young tend to do badly at the ballot box, unless they can add the votes of the old, who vote reliably and in greater numbers.

However, there is one group that votes with even more regularity than the old: the affluent. That nightmarish ICM poll gives Remain a 19-point lead among social grades A to B. YouGov’s latest, showing Leave ahead by a single percentage point, has a Remain lead of 26 points.

There is a wide range of opinions about what turnout will be. My instinct is that the past tends to be a good guide to the future, and that the last time Britain voted on whether to stay in the European Union turnout was ten points lower than the general election it preceded. A turnout of 55 per cent would exaggerate the preferences of the affluent, rather than the elderly – boosting Remain’s chances.

The bookmakers aren’t sold on Brexit

I am deeply sceptical of the value of bookmakers’ odds as a predictive tool. They predicted a Conservative majority in 2010, a hung parliament in 2015 and a victory for Andy Burnham in the Labour leadership race. Seeing as the aim of the bookmakers is to turn a profit not to predict the future, using the bookies’ odds to predict the future feels a bit like buying that there really is a coin under one of the three cups.

Nonetheless, for those who care about such things, it is noteworthy that a Remain vote is heavily favoured in the betting markets.