On 4^th March, Colonel Sergei Skripal, a former intelligence officer in Russian military intelligence (GRU), 66, his 33 year old daughter Yulia and a detective with Wiltshire Police, DS Nick Bailey, were injured in a nerve agent attack on Salisbury. Col Skripal had been exchanged by Moscow in a spy swap in 2010.

The agent used was almost certainly a Soviet-era weapon, Novichok variant A-234, placed on the front door of Col Skripal’s home in powder or gel form. Novichok is a binary agent, i.e. is mixed from two stable and easily transportable precursors. Binary precursors typically have a long shelf life. Although it can be put into aerosol form it’s not normally used as a gas. It’s highly lethal if mixed in the correct proportions, killing within seconds or minutes.

Thankfully all three survived. DS Bailey has now been released from hospital and the Skripals are well on the road to recovery. The lack of lethality strongly suggests that the Novichok precursors were mixed in the wrong ratio, either through a lack of familiarity with Novichok or deliberately, because Porton Down smelt a rat.

In a dramatic statement in the House of Commons Theresa May blamed the Russian Federation, without providing any evidence or suggesting a credible motive. Boris Johnson claimed that the Defence Science and Technology Laboratory at Porton Down had identified the Novichok as Russian. Last Thursday Porton Down dramatically pulled the rug from under May and Johnson. Its Director, Gary Aitkenhead, confirmed that DSTL had not traced the Novichok to Russia.

Right from the beginning the attack had the smell of a false flag about it. Not least, with the presidential election only a fortnight away President Putin had absolutely no motive whatsoever to sanction an assassination in Britain. Indeed, since Col Skripal had been swapped, Russia had every motive not to attack him. Neither the Russian external intelligence agency, the SVR, nor its predecessors the KGB, MVD and NKVD, had ever gone back on a spy swap. The same goes for the GRU.

The SVR have a record of caution in Britain. They have never carried out a hit on British soil. Even the KGB never actually attempted an assassination here. They tasked the Bulgarian CSS with assassinating Bulgarian dissident Georgi Markov in London in 1978, but that now looks to have been a German (DVD) operation, using penetration assets inside the KGB’s First Chief Directorate, designed to undermine détente.

I have not overlooked the 2006 Litvinenko Affair. There is no doubt that Lt-Col Litvinenko was poisoned with Polonium 210, but he didn’t die from it. He was actually killed by the antidote, Prussian Blue, which is metallic, and caused peritonitis. The autopsy report confirming that went walkies and was never shown to that nice man Sir Robert Owen’s, with respect ‘Janet & John’, inquiry. As the Russian prosecutor-general’s office has just pointed out, the Po-210 in question was in London before the two Russian nationals accused of the attack, Andrey Lugovoy and Dimitry Kovtun, not something you will read on Wikipedia.

There was no Po-210 trail from Moscow to London, only the other way around. What’s more, the Po signature was Iranian, not Russian, another material fact withheld from Sir Robert. It was flown from Iran to a cargo airfield near Hamburg. The idea seems to have been to embarrass Vladimir Putin with a staged assassination attempt, which Col Litvinenko was supposed to have survived. Boris Berezovsky, his boss, later very properly topped himself.

At least the Litvinenko smear featured some Russian suspects, a crucial ingredient lacking from the Salisbury smear. No suspicious looking characters with snow on their boots were observed acting strangely in Salisbury on 4^th March! Since they would hardly have wanted to knock off a couple of Jehovah’s Witnesses, the agents placing the Novichok on the door would have needed to maintain observation on it. It’s very difficult to see how a couple of Russian agents would have managed to do that without being spotted.

Novichok does not travel well. It’s dangerous to handle once mixed and ideally the precursors should be combined in laboratory conditions. A couple of Marigolds won’t do. Porton Down, just up the A338, is an obvious candidate, not least as their budget was boosted by £48 million the week after the attack.

The UK in fact has a small stockpile of Novichok precursors, smaller now than it was before 4^th March. So does the USA, ditto the Ukraine and a number of other ex-Soviet republics. During the Cold War the stuff was actually made in Uzbekistan. Some of it definitely went walkies in the chaos following the collapse of the USSR, giving the lie to Theresa May’s claim that only Russia possesses Novichok. Indeed it is far from clear that Russia retained any stocks of Novichok precursors after they officially abandoned the use of chemical weapons. As it happens, the Russians have never liked chemical weapons – the Red Army never used them in World War II.

Theresa May is being typically secretive over Salisbury. The Russian government has put 14 perfectly proper questions to her, none of which have been answered. Amber Rudd has even denied Yulia Skripal’s cousin Viktoria a visa. The Russian Embassy have been denied consular access, in breach of the Vienna Convention, on the unsupported pretext that Yulia Skripal does not wish to see her own embassy. She’s not even being allowed access to her own mobile phone.

In desperation Whitehall has now leaked an intercept from an unknown source in Syria (of all places) to an unknown Russian in Moscow. The intercept looks staged. Aside from anything else a Russian intelligence officer would not report an assassination attempt over an open telephone line.

The allegation against Russia is clearly false and equally clearly linked to Brexit. The only credible candidate for Salisbury is Germany’s covert GO2, which uses Brits and would easily have been able to move around Salisbury without attracting attention.