That trade union ganzer macher Len McCluskey is very cross that Keir Starmer’s Labour Party settled with the antisemitism whistle-blowers last week. “It’s an abuse of members’ money,” he told The Observer. “A lot of it is Unite’s money and I’m already being asked all kinds of questions by my executive.”

The fastest of recaps here: a year ago a Panorama programme featured interviews with a number of former Labour staff members saying that senior figures in Mr Corbyn’s orbit had interfered with the processing of complaints of antisemitism. The party then issued a statement accusing them of being motivated by personal and political hostility to the Labour leader. Believing (and presumably advised) that this constituted a libel, the whistle-blowers took the case to court. Under Keir Starmer the party settled the action with an unreserved apology and paid costs and damages. And it was this payment that McCluskey (or his executive) was so angry about and that constituted the “abuse of members’ money”.

But, you might object, had the party carried on with the case and incurred more costs and then lost in court, wouldn’t that have been an even bigger waste?

Well, according to Len that wouldn’t have happened because Labour’s legal advice had been — he said — just about certain the Labour would win its case against the whistle-blowers. Alas, no one asked him how he knew this, but the former leader Jeremy Corbyn made much the same claim. Their legal bods had told them it was a slam dunk.

The first piece of legal advice I was ever given when I was in my 20s and elected to the executive of the National Union of Students was the “presume you’ll lose” law of libel. Our legal officer said that if I were to accuse someone of something with any degree of looseness and they decided to sue, I should get ready to settle. On the other hand if someone said something about me that I thought grotesquely unfair and I wanted to take legal action, I should assume that I might easily lose. In this way I would avoid spending our members’ money on lost legal cases.

In April 2017 the pro-Corbyn website Skwawkbox made allegations about the anti-Corbyn Labour MP Anna Turley’s application to join the Unite union. The information on which an allegation of dishonesty was based clearly came from the union itself, constituting a data breach. But a Unite official wasalso quoted in the offending article clearly suggesting that Turley’s application had been fraudulent.

Who knows what Unite’s legal advice was back then? Was it, perhaps, that Skwawkbox (whose defence the union funded) and Unite itself had a very good chance of winning? If not, then the Union should have settled. But it pressed ahead, contested the action, and lost. Turley got £75,000 in damages and sought well over £1 million in costs. At which point the union, presumably acting on legal advice, decided to incur even more cost to its members and, despite the trial judge’s refusal of an appeal, tried to take it to the Court of Appeal. In May, Lady Justice Davies ruled against Unite because “no arguable errors of law have been established. The grounds of appeal have no real prospects of success. There is no other compelling reason for the appeal to be heard.”

At this point the reader may (a) be thinking that it is a bit rich for McCluskey to be castigating Keir Starmer about wasting members’ money and (b) wondering how it comes about that a 69-year-old union leader who has just lost the Turley case can reside so much faith in his legal advice.

But what about those members, invoked by McCluskey at the beginning of this article? Aren’t they just furious with Sir Keir? And don’t they very much agree with their leader over the years that much of the antisemitism stuff was got up and exaggerated to damage that champion of the downtrodden, Mr Corbyn?

No. Most of them have no idea it’s even happened. That ruling executive committee invoked by Mr M? There were elections to that body this summer. Eighteen of the seats were uncontested. In the regional and industrial sectors, turn-out averaged 6.2 per cent. The highest turn-out — 19.2 percent — was in the “retired members” section.

The whole edifice of Mr McCluskey’s invocation of his membership is a political Potemkin village. The ordinary workers who pay their dues to be represented over workplace issues have no idea what is being done or said in their names by these self-aggrandising would-be politicians. It’s an illusion, but one that has real consequences.

One day a brave Labour leader will prick this bubble.

David Aaronovitch is a columnist for The Times