Oh dear. According to official sales figures, Peter Mandelson’s The Third Man is flying off the shelves, at number one no less in this week’s non-fiction hardback chart. Could it be that the nervous entreaties of senior Labour figures to ignore the Prince of Darkness and his mysterious book of forbidden secrets actually made people want to read it more? Having read the book, the nervousness strikes me as unfounded and I find the party’s reaction to it more unsettling than anything inside it.

Don’t get me wrong, the book’s not perfect. Much time is spent on Peter generously bestowing his sagacity on one famous person after another. I’m not sure about “The Third Man” as a title, either. By giving himself equal billing to two prime ministers he invites accusations that he’s trying to photoshop himself into the front row of history. It also made me wonder if he’d actually watched the original film to the end, because The Third Man doesn’t come out of it well at all. And the prose is a bit dead, frankly.

Beyond that, the criticisms hurled at the former business secretary seem over the top. It’s said that he brought it out too soon after the election. I suppose eight weeks is quite soon, but the longer he left publishing it, the sooner it would be to the next election. I don’t see what material damage it can do at a time when the party doesn’t yet have a permanent leader or any policy direction. In any case, I thought it was agreed that the Blair-Brown era should be consigned to history. The appearance of histories of it underscores that it is just that – history.

The author has also been attacked for being indiscreet and disloyal, for example by publishing private conversations. Don’t all memoirs do that? (Real question. I genuinely don’t know. The only other memoir I’ve read is Russell Brand’s My Booky Wook and I only got half way). Reading The Third Man, I wish he’d been rather more indiscreet. With his reputation I was expecting something along the lines of Dangerous Liaisons – a complex yet incendiary web of intrigue and revenge. Instead, it’s essentially a confirmation of a now very familiar arc of events, albeit more critical of Tony Blair than I anticipated.

For me the most interesting bit of the book was not the supposedly gossipy stuff hyped up in The Times but the analysis of the defeat. He delivers the one thing that everyone agrees is now absolutely essential: an intellectually honest account of why Labour lost: “The problem was that we were deep in a pile of debt, and still digging. The markets and media knew it. The country felt it… Of course it made sense to emphasise our commitment to the most vulnerable in society, but as long as no one believed us on the public finances, they would not believe us on anything else… [There was a] failure to develop further a vision of the role of the state in society, what government should do more of, what it should do less of.”

It may not be the account that people want to read, but it gets to the heart of the matter of why the public stopped listening to Labour. It’s a shame that the leadership candidates have responded so icily. Their failure to confront the economic record probably accounts for why this contest has failed to resonate with the wider public (The Third Man by contrast has resonated with the British people. It’s outsold both Bill Bryson’s At Home and Peter Andre’s My World – In Pictures and Words. That’s the test).

When it comes to memoirs, I’m sure there are many who would rather curl up with the cosy wrongisms of Tony Benn than confront the hard truths laid bare by Peter Mandelson. Fair enough, each to their own. But it does not bode well for the future of the Labour party if the telling of hard truths becomes equated with disloyalty.