The man-they-love-to-hate is back. Peter Mandelson may be unpopular with his Labour colleagues; but it is the Tories and right-wing press which truly despise him. His crime? Being part of the New Labour team which got Tony Blair elected and consigned the Tories to the footnotes of history for a decade. And now they are, to coin a phrase, ‘dripping pure poison’ on his return to the cabinet.

I hold no brief for Peter Mandelson: I met him once (when I served him a cup of hot water, his favoured tipple, back in my student waitering-to-pay-the-bills days). He strikes me as a fairly tragic figure, a man of immense talents psychologically crippled by his determination to keep his sexuality hidden; how different might his life have been if he’d been born a generation later?

But I’ve been struck by the deep animus he provokes by two separate articles I read in the right-wing media today. First, the Daily Telegraph splashes with the headline Peter Mandelson ‘dripped pure poison’ about Gordon Brown to George Osborne (the shadow chancellor has now been unmasked as the ‘senior Tory’ to whom Mr Mandelson had, recently and allegedly, dissed the Prime Minister).

The Telegraph notes:

Both men have admitted that the meeting had taken place, with Mr Mandelson going further and threatening to reveal what the shadow Chancellor had told him privately about the Conservatives.

How despicable of the Prince of Darkness!, the Telegraph invites us to exclaim. So what quote does the Telegraph produce to back up this malign interpretation of Mr Mandelson’s intent? Here it is, in its full malevolence:

“We talked as much about his colleagues and the state of the Tory party,” he warned. [my italics]

Hmmm, note to the Torygraph: simply adding the verb ‘warned’ after a sentence doesn’t make it so. Sounds to me like the paper’s deputy political editor Robert Winnett is on this occasion more guilty than Mr Mandelson in indulging in the dark arts of spin.

The second example of right-wing anti-Mandelson animus is from Daniel Finkelstein over at The Times’s Comment Central who is horrified by Mr Mandelson’s unabashed disowning of the ‘pure poison’ comments attributed to him:

I must say – and how naive is this – that even after everything, I find the terms of Peter Mandelson’s denial pretty shocking.

Fair enough, you might say. Peter Mandelson does, after all, have a history of issuing statements which are not always reconcilable with the actualite.

But there’s a crucial point missing from both the Telegraph article and Da Fink’s blog: any questioning of how the private conversation between Mr Mandelson and Mr Osborne was made public in the first place. One of two people, after all, must have disclosed what happened: a cabinet minister, or a shadow cabinet minister. Isn’t it interesting to know which one?

Key question to be asked, therefore: to whose advantage is it to leak the story? Well, there’s a clear answer to that: not Peter Mandelson’s. Which narrows down the list of suspects somewhat.

Next key question: has George Osborne got form? Yes he does, and here we can rely on Mr Finkelstein’s own testimony: “I happened to talk to the top Tory involved within a few hours of the reported conversation. The person recounted the conversation to me in outline but confirming that Mr Mandelson had been extremely critical of the Prime Minister.”

So, at the risk of teetering onto the quicksand of libel, I think we might reasonable conclude that it was George Osborne who was responsible for leaking to the media the contents of his private conversation with Peter Mandelson.

Which prompts me to ask the question: exactly how would the Telegraph or Times have reported all this if it had been Mr Mandelson leaking to the media the contents of a private conversation with George Osborne in order to embarrass the shadow chancellor? Let me presume to supply an answer: with predictable outrage, and probably demands for Mr Mandelson to go for a resignation hat-trick.

There’s a principle at stake here, even if it’s one increasingly regarded as old-fashioned: that private conversations held in good faith should be respected.

Few will spare much sympathy for Mr Mandelson – he leaks at least as much as he is leaked against – but if Daniel Finkelstein is going to be “pretty shocked” by anyone’s behaviour in this little episode he should perhaps ask if George Osborne has displayed the traditional values of decency which Tories seem more keen to hold others to than to live up to themselves.