It now looks pretty clear that the Conservatives have not enjoyed a sustained "referendum" surge in opinion polls following David Cameron’s promise of an in/out vote on EU membership.
A new ICM poll for the Guardian  has Labour on 41 per cent and the Tories on 29 per cent, respectively up threee points and down four on their January ratings. (The Lib Dems are down two to 13 per cent and Ukip are up three to 9 per cent). The daily YouGov tracker has been telling a similar story.
This will come as a bitter disappointment to those Conservative strategists who thought the referendum gambit would change the game at Westminster. On the day of the big speech there was some quite exuberant cherishing of the Prime Minister’s presumed master-stroke. (Some of us were, ahem, less sure about that. )
There are all sorts of reasons why the Tories might not have enjoyed a great revival on the back of a promise to hold a plebiscite in 2017 when, after all, they may no longer be in government. GDP figures showing the economy still lifeless took the rosy glow off that week’s news for Cameron. There has since been a carnival of Tory division, with mutterings about the leadership ambitions of obscure Conservative challengers and a parade of the dinosaur tendency in hostility to gay marriage.
Even so the Tories would have hoped to see Ukip floundering in the wake of the referendum offer and, perhaps, to have scooped up the support of some eurosceptic ex-Labour undecided voters. But for that to happen, there would have to be lots of people for whom Britain’s membership of the EU is a pressing issue. The evidence shows that isn’t the case, with the numbers citing it as a top concern in steady decline  since the late 1990s. Interestingly, this latest ICM poll also shows a decline in the number of people citing eurozone turbulence as the likeliest cause of our economic travails. That makes sense since there have been far fewer Eurogeddon headlines this year as the debt crisis in the single currency area appears – for the time being at least – to have stabilised.
So the people who care passionately about the EU, or rather, who despise it with a passion and are minded to choose a party on that basis, are pretty much the same people who have always felt that way. There are enough of them to flatter Nigel Farage’s ego (and send shivers up the spines of Tory MPs), but not enough to turn the Tory poll deficit into a lead.
What is more, those who obsess about the EU and flirt with Ukip as a way of expressing that feeling are, as Lord Ashcroft’s detailed polling has shown , channelling a wider scorn for politics and mainstream parties in general. Their Europhobia is bundled up with anger about crime, immigration and an inchoate mix of dislocation and anxiety about British or English identity.
In that context, Cameron’s pledge to consult the country any time other than right now looks like just another sleight of hand. Anyone concerned enough about colonisation by Brussels to get really excited about a referendum will also remember the Tory leader’s "cast iron" pledge to hold a vote on the Lisbon Treaty, which melted away as soon as he moved into Downing Street.
Having been in Eastleigh, canvassing opinion ahead of the by-election for Chris Huhne’s old seat, I can report that no-one I spoke to thought a European referendum at all likely to make them vote Conservative. (Of course, journalists vox-popping random punters is no statistical measure of anything, so my experience doesn’t prove much.) I encountered some half-hearted Labour voters who wished Ed Miliband would come out and fight more vigorously in favour of our EU membership; I met a few Ukip voters – ex-Tories mainly – who said they didn’t care what Cameron said about referendums and whatnot because only Farage’s party was reliably dedicated to the anti-Brussels cause.
Senior Tories insist their referendum gambit was never meant to turn the party’s fortunes around overnight. (They also point, reasonably enough, to Cameron’s EU budget negotiation success last weekend as evidence to rebut the pro-European claim that his domestic manoeuvres guaranteed diplomatic isolation.) The view at Tory high command remains that, come a 2015 election, the broad swath of eurosceptic voters will face a choice between one plausible governing party that wants a referendum and one big challenger that doesn’t. The message is simple: if you want that referendum, vote Conservative. Even Ukip voters who might toy with Farage mid-term, when faced with the hazard of letting Ed Miliband into Downing Street, should then come home to the Tories in a general election.
That is quite possible. Yet I’m not entirely convinced it will work. For one thing, as I’ve argued before, if Miliband really needs a referendum in his manifesto he can hide behind belated support for the 2011 European Union act to smuggle one in. But more important, the problem of trust in Cameron on the right is not credibly addressed by a "jam tomorrow" referendum bid. Besides, the Prime Minister has said he passionately wants the UK to stay in the EU, albeit on renegotiated terms. For angry, disillusioned ex-Tories, that sentiment places him still on the wrong side of a cultural divide, lumped together with the other cosy Brussels-loving elitists. If the hardline Europhobic vote is indeed an expression of more profound, nationalistic alienation from the Westminster game, it seems doubtful that Cameron has the credentials to win it back for the Tories. He’ll have to find his poll surge elsewhere.