IT was a gripping speech. David Davis read it well. I don’t say he wrote it well, but he read it competently enough on his old friend’s behalf.

But was Tuesday’s intervention, under protection of parliamentary privilege, enough to stand up Alex Salmond’s central thesis - that he was the victim of a high-level plot to ruin and even imprison him?

Not even the former Brexit Secretary went that far, despite an unguessable ‘whistleblower’ conveniently punting dozens of secret messages his way.

Instead, Mr Davis told the Commons: “No single sequence of texts is going to provide conclusive proof of what the whistleblower described as a ‘criminal conspiracy’, but it does show a very strong prima facie case, which demands further serious investigation.

“By which I mean, at the very least, a thorough review of all the emails and other electronic records for the relevant personnel at all relevant times.”

The messages, he said, showed three senior members of the SNP, including Nicola Sturgeon’s husband, the party chief executive Peter Murrell, were part of a “concerted effort” to encourage police complaints against Mr Salmond in late 2018.

The Holyrood inquiry into the Salmond affair has the same material, which was downloaded from an SNP staffer’s phone for the former First Minister’s criminal trial, after extracting it from the Crown Office.

However MSPs have decided not to release it on the grounds it doesn’t show the plot Mr Salmond claims.

Yes, SNP personnel were blunt about their old boss, and did play amateur sleuths over complaints, but that does not a conspiracy make.

And it is quite a conspiracy Mr Salmond is suggesting - that a raft of powerful people would have put him behind bars as part of a media management strategy gone rogue.

To spare Ms Sturgeon pain over his judicial review of the Government’s bungled sexual misconduct probe into him, the First Minister’s allies encouraged police complaints to move the story on, leading to a trial at which, despite the plotters’ best efforts, Mr Salmond was acquitted on all counts.

The proof, he claims, is in that secret stash of text messages between Mr Murrell and others.

But the reason the material wasn’t put before the jury in the trial is that the judge Lady Dorrian didn’t rate it.

It was “collateral” to the charges on the indictment, she ruled.

In one preliminary hearing, Mr Salmond’s QC told her: “We have people who did not want to complain encouraged to complain.”

To which she replied: “But we often hear in these courts that people do not want to complain.”

Ah, but this went “beyond that”, the QC said, an attempt to bulk up weak complaints to make them criminal.

Lady Dorrian was unimpressed.

“There’s nothing wrong with encouraging people to cooperate with the police. The assertion that a witness did so improperly requires to have a proper basis,” she said. Quite so.

Lord knows, the Salmond affair has exposed all manner of shabby, misguided and derelict behaviour at the top of Government and the SNP.

The First Minister does not appear to have been straight with Holyrood about what she knew and when. There are very serious questions about the credibility of her chief of staff.

Mr Murrell’s evidence to MSPs seemed as selective as it was defective.

John Swinney’s self-debasement has been horrible to watch. He scuttled his reputation with a cynical frustration of the inquiry, holding back highly pertinent legal advice about Mr Salmond’s civil case until the FM’s oral evidence session was behind her.

Had he provided it honourably on time, it would undoubtedly have led to difficult questions for her.

Instead, he sat on it, smothering his once good name in the process.

The Lord Advocate looks naive. Frantic warnings from external counsel that the Government’s case was on the skids were “discounted”, leading to a deepening mess.

Civil servants made shocking, elementary mistakes at the outset of the complaints process, then had to have the truth wrung out of them.

Duds who ought to have been shown the door or precipitously demoted are inexplicably still in their jobs.

But has Mr Salmond’s wicked plot been proved? I’d say not.

There is another way to look at those text messages. Rather than a contrived bid to protect Ms Sturgeon, they may simply have been born out of a genuine belief that Mr Salmond was a lecherous menace who deserved a reckoning with the justice system.

As his trial showed, he did behave inappropriately with colleagues and was drunkenly game for adultery.

He may not like to think too much about that, but it doesn’t mean people only took action because of a plot.

Conspiracies are in the eye of the beholder, and Mr Salmond has made a comfort blanket out of his. It’s easier being the victim than the villain.

You may also wonder if his anger is rooted in a Trump-style presumption that people in the Government and SNP owed him their absolute loyalty.

One of the most intriguing comments in his inquiry testimony last month was about those messages.

“What they speak to is behaviour that I would never have countenanced from people I had known, in some cases, for 30 years,” he said.

As if people who had known him for 30 years should have taken their shared history into account.

But if people had bitten their tongues, regardless of their misgivings and information gleaned from complainers, that really would be a conspiracy - a conspiracy of silence.

Mr Salmond’s anger may therefore be the rage of Caliban seeing his reflection in the mirror, the sound of a fragile ego being punctured and deflating with an agonised shriek.

To the tinfoil diehards, the inquiry’s refusal to publish the text messages will only confirm the breathtaking extent of the plot. Wow, even the opposition at Holyrood is in on it.

The bug-eyed bores with theories about the death of Willie McRae and MI5 fifth columnists will see the Salmond files as part of the same endless Unionist web. The conspiracy shall never die, and all that.

But to most people, I suspect, Mr Salmond just looks like a grubby has-been who can’t handle the truth.