The Shikhany research base, 500 miles from Moscow, is thought to have produced the novichok poison. The facility also contains shops, hospitals and schools GOOGLE

A Russian military research base has been identified as the source of the nerve agent used at Salisbury in a British intelligence briefing for its allies, The Times has learnt.

It was used to persuade world leaders that Moscow was behind the poisoning and said that the novichok chemical was manufactured at the Shikhany facility in southwest Russia.

The briefing led to the expulsion of more than 150 Russian diplomats from 28 countries. Also included was information suggesting that Shikhany, Russia’s equivalent of the defence laboratory at Porton Down, was used during the past decade to test whether novichok could be effective for assassinations abroad. The weapons-grade nerve agent was used to poison the former double agent Sergei Skripal and his daughter, Yulia, a month…