McKeigue & Robinson, "Doubts About 'Novichoks' ", Working Group on Syria, Propaganda and Media (March 2018)
The link is to a briefing note by the Working Group on Syria, Media and Propaganda authored by Professors Paul McKeigue and Piers Robinson. It is important to bear in mind that the note reflects work in progress, but that "the substantive questions raised need answering, especially given the seriousness of the political crisis that is now developing." They welcome comments and corrections.
1) There are reasons to doubt that these compounds are military grade nerve agents or that a Russian “Novichok” programme ever existed. If they were potentially usable as chemical weapons, people on the OPCW Scientific Advisory Board who were in a position to know the properties of these compounds would have recommended that they be added to the list of Scheduled Chemicals. They have never been added. Journalists who wish to investigate this could start by asking members of the Scientific Advisory Board for 2013, who are listed in the Appendix of this document (page 14). [External PDF: https://www.opcw.org/fileadmin/OPCW/SAB/en/sab-20-01_e_.pdf]
2) Synthesis at bench scale of organic chemicals such as the purported “Novichoks” is within the capability of a modern chemistry laboratory. Porton Down itself must have been able to synthesize these compounds in order to develop tests for them. The detection of such a compound does not establish Russian origin.
For further details, please see the briefing note itself.