If, to borrow Harold Wilson's dictum, a week is a long time in politics, it's not hard to see why some in Labour are dismissing today's Telegraph splash [2] ("Ed Balls's 'brutal' plot to overthrow Tony Blair") as "ancient history" [3]. But the story deserves more scrutiny than that.The paper has obtained a cache of 36 leaked documents [4] outlining how Ed Balls and Ed Miliband fought to get Gordon Brown into Number 10 within weeks of the 2005 general election. The private papers, which belong to Balls, contain no single, startling revelation and will be of interest to few other than Westminster Kremlinologists. But there is no doubt that they are damaging to the shadow chancellor. They contradict his public insistence that he never sought to undermine Blair (just a year ago he dismissed claims [5] that he was disloyal to the former PM as "balderdash") and will hinder his attempts to detoxify his brand.

Then there's the question of why, six years on, these documents have come to light now. Balls says he last saw [6] the papers in a file on his desk at the education department shortly before the 2010 election. The shadow chancellor is not a man short of enemies in either Labour or the Conservative Party and the documents are almost certain to have been leaked by a political opponent. Sir Gus O'Donnell, the cabinet secretary, has already sanctioned an investigation into the loss of the papers. At a time when the government's economic strategy is under increasingy scrutiny, partly thanks to Balls's efforts as shadow chancellor, the leak is highly convenient, to say the least.

In devoting so much attention to this story the Telegraph is aiming to use Balls and Miliband's past to damage their present. Whether it will succeed is another matter. The documents might fascinate the Westminster village but they will be of little concern to the public, most of whom long ago lost interest in the TB-GB psychodrama. The Damian McBride scandal inflicted considerable damage [7] on Labour's poll rating but other revelations, such as those of Gordon Brown's "bullying", failed to do so. The Tories, however, who pointedly refer to Balls as a "man with a past" will still welcome these papers as political gold.