The most worrying thing about the Balls-Miliband story for Labour

The key point about the email by a Miliband adviser describing Balls as "a nightmare" is that it was leaked in the first place.

Ed Miliband and Ed Balls at the Labour conference in Brighton in September. Photograph: Getty Images.

Update: I've now learned how the email was really leaked.

The Tories have leapt gleefully on today's Mail on Sunday story revealing that Miliband staffer Torsten Bell, Labour's director of policy and rebuttal, referred to Ed Balls as a "nightmare" in a private email. After Balls's special adviser Alex Belardinelli wrote in a group email on the shadow chancellor's planned response to the Bank of England's upgraded growth forecasts, "Could we get this out pls? cleared at this end and essentially the same script as we had on GDP day the other week", Bell (a former special adviser to Alistair Darling during his time as Chancellor) wrote to fellow Miliband adviser Greg Beales: "As an example of why we're having problems on EB messaging-this is his current three part argument: cost of living, recovery built to last, economy works for working people. Nightmare." Beales replied: "When did built to last become a part of our thing?"

That there are tensions between Miliband and Balls has long been an open secret in Westminster. The Labour leader's team have privately accused the shadow chancellor, who was not Miliband's first choice for the job, of being insufficiently committed to his responsible capitalism agenda and too focused on defending the record of the last Labour government. There also differences between the pair over HS2 and the proposed third runway at Heathrow, with Balls openly favouring the latter over the former, the reverse of Miliband's position.

What is peculiar about the disagreement revealed by the emails is that it is so minor. Miliband himself has regularly used the phrase "built to last" (a key part of Barack Obama's 2012 campaign) and even the most dedicated Labour Kremlinologist would struggle to spot any difference between Balls's three-part argument and Miliband's. Indeed, I'm told the pair met before the publication of the recent GDP figures to discuss and agree on Labour's response, which last Wednesday's quote from Balls (on the BoE's growth forecasts) was almost identical to.

A Miliband spokesman has responded by effectively stating that Bell was wrong: "Ed Balls was entirely right. After three damaging years of flatlining, there is no recovery for millions of families. Prices are rising faster than wages, and figures this week showed that people are on average £1,600 a year worse off since David Cameron came to office."

That this apparently trivial disagreement (what Freud called "the narcissism of small differences") led Bell to refer to Balls as a "nightmare" is evidence of how great the mistrust is. The mutual suspicion will be compounded by the key point of the story: that the emails were leaked in the first place. Assuming that the leak was intentional (and not the result of a lost phone or misplaced documents), this is a red-on-red attack, delivered via a hostile newspaper. If history is not to repeat itself, both sides would be wise to ensure it is the last.

And as Balls comes under increasing attack, largely prompted by the false belief that he has been proved wrong by the return of economic growth, it's worth remembering that there is no one better qualified to perform the job of Chancellor.