Labour should call for an EU referendum on election day

Keith Vaz isn't often right, but he's right today. "An in / out referendum before the next election would clear the air," he tweeted. "We could actually hold it on the day of the next general election."

His view is presumably less influenced by his desire to "clear the air" than it is by basic political strategy, but his basic political strategy is a very good one.

Labour's shadow Europe minister, Emma Reynolds, is in Vienna today outlining the party's policy on Europe. Miliband's in a bit of a bind. The Labour leader does actually believe he will be prime minister come 2015, and he doesn't intend to spend the entire time bickering over Europe. But nor does he want to end up on the wrong side of voters' opinions on the EU by opposing a referendum come election time. Tricky. Luckily for Miliband, Vaz has provided the least bad option: demand a vote in 2015.

Today's intervention by Nigel Lawson shows quite how damaging David Cameron's EU referendum pledge will prove to be. No matter what deal he secures in Europe (and it is unlikely to be impressive) there is a substantial minority of core eurosceptics in the Tory party who will vote 'no'. Lawson's intervention fires the starting gun on the debate. Now that a senior, former pro-Europe political figure has broken ranks, they can do so under some degree of cover.

Why should Labour wait until after the election for the Tories to destroy themselves? Why not force them to destroy themselves during a general election campaign? Having now won the fight for a referendum, eurosceptic Tories will soon have to acknowledge the idea that their leadership is going to run a pro-EU campaign. From Labour's perspective, there is no better time for that campaign to be fought than during a general election. Voters will be put off by a party whose leadership and backbenchers are so substantially at odds and whose concerns centre on their pet hates rather than the subject of the economy. The party's Ukip-centred anxiety attack will become a full-blown nervous breakdown.

The Tories have already shown they will fall for this sort of trap. Fifty-three Tory MPs backed Labour on the EU budget and defeated the government, despite Ed Balls' trap having all the subtlety of a Tom and Jerry cartoon.

Even better, it would kill off one of George Osborne's much-loved dividing lines. As things stand, the Tories believe they have Labour on the wrong side of public opinion on Europe, much as they do on welfare and the European Convention of Human Rights. By demanding a referendum early, Labour can paint itself as more committed to a public say on the EU than the Tories are. By the time the party is campaigning for the UK to stay in, it will be joined in the endeavour by the Conservative party.

The Tories will claim there is not enough time before 2015 for Cameron to secure a good deal for the UK. Labour can simply claim that there is. In truth, no amount of time would be enough for Cameron to secure a credible deal, given he has already revealed his hand. Cameron's negotiations are a doomed endeavour.

Will the Tories play ball? Absolutely not. The chances of having an EU referendum on voting day are slim-to-none. And that's all the better for Labour. If the Tories refuse to hold the referendum on election day, Labour will find itself on the right side of the issue – pushing for a more robust EU policy than Cameron is prepared to deliver. If the Tories do agree to hold a referendum, it will do them more damage than it will Labour.