Salisbury attack: Russia challenges UK to prove it was behind spy poisoning by presenting evidence in The Hague

Russia has demanded the UK present "every possible element of evidence" that it was responsible for the Salisbury nerve agent attack on a former spy that triggered a global diplomatic row and plunged its relationship with many Western nations to lows not seen since the Cold War.

Yury Filatov, Moscow's ambassador to Ireland, said it had asked the Executive Council of the Organisation for the Prohibition of Chemical Weapons (OPCW), which has been investigating at the scene of the poisoning of Sergei Skripal and his daugher, Yulia, to call an extraordinary session in The Hague tomorrow.

"We hope to discuss the whole matter and call on Britain to provide every possible element of evidence they might have in their hands," he said.

"Russia is interested in establishing the whole truth of the matter and we hope certainly that this meeting will help to return to at least the realm of normality within the realm of international law and, let's put it, decency in international relations."

Moscow has consistently denied being responsible for the chemical attack, which left Mr Skripal and his daughter fighting for their lives in hospital, and prompted Britain and two dozen of its allies to expel more than 150 Russian diplomats. Russia has ordered the same number to leave in a tit-for-tat response.

Mr Filatov claimed people in Europe do not trust the British government's version of events.

"Even countries which took part in solidarity demands (expelling diplomats) have doubts," he said.

"Britain acted, as we know, on grounds that have nothing to do with Salisbury but mainly to do with some other agenda."

The ambassador's demand came on the same day a former Russian general said that the attack could trigger "the last war in the history of mankind".

Speaking on BBC Radio 4's Today programme, Evgeny Buzhinsky said that the West is "cornering Russia and to corner Russia is a very dangerous thing."

"If the situation develops in the way it is now, it will end up in a very bad outcome," he added.

When asked what he meant, the General said: "A real war, it will be the last war in the history of mankind."

Asked whether there was a real risk of triggering a war, a spokesman for the Theresa May said Britain was responding to the attack in a "proportionate way".

"We need to respond in a proportionate way to this aggressive behaviour from Russia and that's what we're doing," the spokesman said.

On Monday, Russia's foreign minister accused the UK of "putting all decency aside" over its claims that Moscow is to blame for the poisoning.

Sergei Lavrov appeared to suggest UK secret services may have been involved in the March 4 attack in Salisbury, which he said the British government may have found "beneficial" as a distraction from Brexit.

Mr Lavrov said it was "outrageous" Britain had failed to provide consular access to Ms Skripal since it emerged that her condition was improving.

His comments came as the Russian Embassy in London issued a series of what it termed "questions without answer" about the Skripal case - including whether the UK had ever produced novichok.

Britain has consistently maintained the Russian state must be behind the attack.

Agencies contributed to this report