Some long while ago, far away in the vast, misty caverns of time, there was a by-election in Glasgow that Labour lost. It may be hard to recall the debates in the Labour Party of the last weekend but one, yet historical research uncovers a subsequent period of media stories based almost entirely upon the utterances of anonymous sources.

I began to wonder, with apologies to Edward Lear, who, or why, or which, or what, was involved in the plot? Things reached their nadir with the invocation of that sociologically unlikely category, “friends of Mr Hoon”.

I have often wondered what would happen if newspapers and broadcasters were to sign a self-denying ordinance, refusing to print or repeat anything supposedly said by an anonymous source, whether “friend of”, “close to” or “senior” (and since when was any source ever described as a “no-mark backbencher”, a “convenient quote-hanger” or an “inconsequential former minister”?). It is hard to believe that the consequences of such a pact would make things any worse for the conscientious reader, attempting to work out what is actually going on.

Of course, some disgruntled Labour MPs, in those pre-Miliband times, may have had good additional reason for seeking anonymity. Were any of these sources calling for Gordon Brown's departure, the same sources who had called for Tony Blair's demise 22 months earlier? If so, you could see why they might be embarrassed. Some columnists I can think of, on other newspapers, make me blush with their weather-vane “we thought Gordon was marvellous but he has proved us wrong” schtick, as if, somehow, the man whom they had so praised for the decade of his slow premiership campaign had grown unexpected hair and teeth on a full-moon night last autumn.

Don't you recall all your guff about him not being flashy like Bad Blair, but that being a big plus? You changed, oh Guardianistas, not him; he wasn't as good as you said he was, and he isn't as bad as you now paint him. The moronising of Gordon Brown - just the latest killing in our series of assassinations of public figures - is an unlovely aspect of the national debate.

But the anonymous phase ended with the famous David Miliband article of last Wednesday, since when quite a lot of stuff has gone on the record, a lot of it overblown, some of it twaddle, some of it sensible. Under the heading of “twaddle” we might put any story purporting to use opinion polls as a way of predicting whether a Miliband leadership might be good or bad for Labour. Not that many people in Britain know very much about the Foreign Secretary, just as very few knew much about David Cameron before the autumn of 2005.

“Overblown” describes the almost universal judgment that the Miliband article in The Guardian was nothing but a blatant challenge for Mr Brown's job. This is an over-interpretation, based on the current rules of media-political debate, which demand that anything other than nothing must be everything. It must be a leadership challenge, a bid for Mr Brown's job, or it must be windy verbiage. And it cannot be the latter since Mr Miliband would have known that whatever he said would be seen (by the media) as a leadership challenge, and therefore in saying anything he was effectively mounting such a challenge.

This analysis simply fails, I think, to understand Mr Miliband's dilemma. Contrary to the depiction of Mr Blair by the more purblind Brownites as a shallow celeb-style super-emoter, the former PM was, above all, a supreme advocate. Lawyers do well in politics for a reason, and the reason is that leadership is about persuasion. Mr Blair never stopped arguing, never stopped constructing arguments, never stopped advocating. He wasted little time on anything else, such as anger, envy or regret.

What Mr Miliband can see is that Labour currently has no argument. For ten months now the Conservatives - and in Scotland, the Scottish Nationalists - have been allowed to romp around in the policy meadows, contradicting themselves, making stuff up, turning somersaults, and no one in the Labour Party has laid a glove on them. This is also the real sense of the leaked (if elderly) Blair memo, which followed so handily upon the Milipiece.

Instead Labour has been all over the place. Its panics have detracted from its genuine achievements, tactics have negated strategy, the unions have been flattered when they should have been criticised - how can you, in one breath, have your members strike over pay, and in the next drone on about the special “public sector ethos” that they supposedly possess?

In this situation leading Labour figures have a number of options - all of them bad. They can try to chuck out Mr Brown (which Labour rules make very difficult) and hope to avoid meltdown at the next general election - though at the possible cost of using up the next Labour Prime Minister too. They can soldier on and hope that economic upturn and boredom with the “Kill Gordon” narrative meliorates the scale of their defeat. They may even believe that upturn plus a new PM could save them. But whichever solution they end up with, the party's long-term future depends upon it having an argument to put to the country. There is no room here in this article for what that argument is, but I believe it is in the territory of what ex-Brownites wrongly describe as the “über-Blairites”.

This was Mr Miliband's point. Of course, he was also reminding the party and the country that he is available to pursue such an argument - his marker was being put down. If and when Mr Brown goes, Mr Miliband wants to succeed him. But it is far from being narcissism, as Jon Cruddas described it over the weekend.

It is as much of an irony that Mr Cruddas should criticise Mr Miliband for using column inches that might have been devoted to attacking Tories as it is to have that licensed buffoon, Robert Marshall-Andrews, assail the Foreign Secretary for disloyalty. Tory advance will do for the preposterous QC what his own party should have done years ago, but it is a reminder that one of any new leader's pressing tasks will be the cleansing of the Augean stables of his or her own back benches. What terrible crud accumulates over time!

Unlike my more prescient colleagues I don't know whether Gordon Brown will still be Prime Minister in a year's time. I do know that the very last thing he should do is to take the advice of those commentators and MPs who are urging him to sack Mr Miliband. Far better for him to think hard about creating the best circumstances in which Mr Miliband, or one of his generation, can become Labour leader.

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