Russia has ordered the expulsion of 23 British diplomats in Moscow as the tension between the two countries deepens. It's in retaliation for Britain ordering out the same number of Russian diplomats. All of this is in response to a nerve agent attack on a former Russian double-agent. Richard Bestic reports from London.

The Russian Foreign Ministry's expulsions had been anticipated. Indeed, Britain's ambassador to Moscow, Laurie Bristow, was inside the building for just 10 minutes receiving the names of those who'd be getting on a flight home. As well as expulsions, Moscow's also added the closure of the British Council cultural centre in Russia and an end to plans for a reopening of a Consulate in St Petersburg. The expulsion numbers exactly mirror those expelled by the British at the Russian Embassy in London, The row a nerve agent attack in Britain on former Russian spy Sergei Skripal and his daughter Yulia, both still critically ill in hospital.

UK Prime Minister Theresa May was briefed by police chiefs at the scene of the attack, saying the diplomatic expulsions in Moscow change nothing.

THERESA MAY BRITISH PRIME MINISTER "Russia's response doesn't change the facts of the matter. The attempted assassination of two people on British soil for which there is no alternative conclusion other than that the Russian state was culpable. It is Russia that is in flagrant breach of international law and the Chemical Weapons Convention."

Russian Foreign Minister Sergei Lavrov in Kazakhstan accused the UK of failing to produce real evidence of Russian involvement in the nerve agent attack and misleading the public.

RICHARD BESTIC LONDON "On Monday the European Union meets to discuss the deepening crisis between London and Moscow, many member states in the EU calling for a heightening of sanctions against Russia."

French President Emmanuel Macron and German Chancellor Angela Merkel said this week they both stood by the UK and were considering next steps. RB, CGTN, London.