24/01/2013 09:55 GMT | Updated 26/03/2013 05:12 GMT

Ed Miliband's EU Referendum pledge Shows Why He's Not Up to Being Prime Minister

Ed Miliband has been on the up. That's not saying much of course, because the starting point was that the public thought of him as a brother-knifing, out-of-touch geek who was largely incompetent (except at knifing his brother, that is). There wasn't really any lower for him to go, unless he'd taken to Twitter to ask why Lord McAlpine was trending.

However, let's give credit where it's due. For a while, things have slowly been getting better for Ed. He's become a little less awkward, a little more normal, and a little more competent. His speech at Labour Party Conference, if not exactly a tour de force, was pretty solid. With a consistent if unspectacular lead in the polls, it seemed a lot more possible that he might become prime minister at the next election, even if he might require the help of the Lib Dems to do so. More importantly, he was starting to look like a plausible candidate for the job.

Fast forward to PMQs yesterday, and his first few questions were in line with this steady improvement. Ed was finger wagging like a nasty schoolmistress, but by and large he was on track. But then, we saw the difference between a man cut out to be prime minister and another who just doesn't have the judgment to ever lead the country well. On Ed's beloved Rubik's cube, a wrong turn can be undone in a quick readjustment, but for someone aspiring to lead the country, there is no such latitude. Goaded by the prime minister, Ed squirmed and squirmed until he proudly proclaimed that Labour was against an in-out referendum on the EU.

This was a massive mistake, for a number of reasons - and, most obviously, because most people would actually like to see a referendum. Here's the rub: Ed, who was brought up in an intellectual enclave in North London, doesn't realise that there are two types of people who want to have a vote on this. There's the staunch anti-Europe lot who want to get out of the EU at all costs and who will jump at the chance to take any road that will lead away from Brussels - and some of them vote Labour. Much more importantly, though, there is a wider group who think that it's right that the public's voice is heard, regardless of how the vote goes.

The EU plays an enormous part in the governance of our country and has huge sway over many aspects of our daily life. People should be allowed to have their say on fundamental constitutional issues - and just as it's appropriate to vote on devolution or on the voting system itself, so we must allow people to choose whether they want so much control to be had by Brussels. Even if you believe in Scottish Independence, you'd be hard pressed to argue that it should be achieved without asking the people first - and why should the handover of power to Europe be any different? Ed's inability to see this reeks of the awkward, brother-knifing image from before, of a left-wing intellectual who is out of touch with normal people.

As if it wasn't bad enough that Ed came out against a referendum, it was particularly ill-judged to commit himself so long before an election. There can have been no time to carry out internal polling, or to gauge opinion amongst his party. That's why Labour MPs were suddenly forced to change their lines of attack after PMQs, as nobody expected Ed to give a clear pledge. Now he's left exposed - either looking like he's on the wrong side of the argument, or that he's flip-flopped on a huge issue.

It came to the crunch - and Ed failed the big test, reversing the hard work of the past year. He may yet still become prime minister, but he's reminded the public that he will never be prime ministerial.