Former Russian spy Sergei Skripal and his daughter, Yulia Skripal, were found unresponsive in a U.K. shopping center on Sunday, and authorities now believe the pair were intentionally poisoned with nerve gas.
Both father and daughter remain at the hospital in critical condition.
The medical and chemical evidence and the effects on the victims point to a nerve agent. Sources would not discuss which one. The best known are VX and sarin.
Although further details are awaited, the suspicion in Downing Street will be that the Kremlin has carried out another brazen assassination operation on British soil.
Several agencies, including Scotland Yard’s counter-terrorism command, SO15, are working to uncover where the nerve gas came from and whether there is more located somewhere in the U.K.
Chemical weapons experts said it was almost impossible to make nerve agents without training. “This needs expertise and a special place to make it or you will kill yourself. It’s only a small amount, but you don’t make this in your kitchen,” one said, speaking on condition of anonymity.
Though there is nothing definitive regarding Russian involvement in the poisonings and authorities have cautioned against speculation, some experts believe the international climate is such that Russia would feel confident undertaking an assassination on British soil.
One former senior Foreign Office adviser suggested the Kremlin was taking advantage of the UK’s lack of allies in the US and EU. He said the British government was in a “weaker position” than in 2006 when two Kremlin assassins poisoned the former FSB officer Alexander Litvinenko with a radioactive cup of tea.
The adviser said the use of nerve agent suggested a state operation, adding that its deployment in the centre of a sleepy cathedral city on a Sunday afternoon was “brazen”. “It says a lot about how seriously they [the Russians] take us that they feel able to do something like this,” the ex-adviser said.
He added: “The Soviets used to use bespoke toxins in their assassination programme. They require a lot of capacity in research and development. You need to produce, manufacture and store them.”
More information will come in a few days when toxicology reports are analyzed.
In the interim, authorities are seeking to speak with anyone who was in the vicinity of the attack in the hours prior to the victims being found, particularly hoping to discover cell phone video of the scene.