Theresa May dramatically pointed the finger at Vladimir Putin tonight over the nerve gas attack on a former spy.
The Prime Minister said the facts increasingly suggested Russia was behind the apparent 'hit' on double-agent Sergei Skripal in Salisbury.
Branding the attack a 'reckless and despicable act', Mrs May said the substance used was a 'military grade' agent Moscow has produced.
Together with Russia's previous actions and tactics, including the killing of Alexander Litvinenko, the UK authorities had concluded it was 'highly likely' to be involved in the episode.
In a tough statement updating MPs after a meeting of the National Security Council, Mrs May raised the prospect of significant retaliation - making clear that the UK is already consulting Nato and other allies.
'It is now clear that Mr Skripal and his daughter were poisoned with military grade nerve agent of a type developed by Russia,' Mrs May said.
'This is part of a group of nerve agents known as novichok.'
Russia's ambassador was summoned to the Foreign Office at 3.45 for a 'cool but firm' meeting with Boris Johnson. There was no handshake between the politicians as Mr Johnson outlined the 'outrage' felt by the British people.