https://www.rt.com/news/424149-skripal-poisoning-bz-lavrov/
The Russian foreign minister said that London refused to answer dozens of “very specific” questions asked by Moscow about the Salisbury case, as well as to provide any substantial evidence that could shed light on the incident. Instead, the UK accused Russia of failing to answer its own questions, he said, adding that, in fact, London did not ask any questions but wanted Moscow to admit that it was responsible for the delivery of the chemical agent to the UK.
https://www.unz.com/article/tracing-the-rush-to-war/
The technical ability of Porton Down to identify a chemical has never been in doubt, and the only “finding of the United Kingdom”the OPCW has confirmed is the identity of the chemical.
There are scores of countries that chemical could have come from. For the BBC and other mainstream media outlets to pretend that the OPCW has in any sense endorsed Boris Johnson’s claims about Russia is to spread deliberate lies as propaganda. In fact what they have confirmed is simply the finding of Porton Down – and that finding was that it is a chemical which cannot be confirmed as made in Russia.