The EU has recalled its ambassador to Moscow after leaders agreed it was "highly likely" Russia was responsible for a nerve agent attack in the UK.

In a statement, the European Council of EU leaders agreed "there is no plausible alternative explanation".

Moscow denies responsibility for the attack on an ex-spy and his daughter.

Meanwhile, a convoy of vehicles was seen leaving the British Embassy in Moscow ahead of Russia's deadline for 23 UK diplomats to leave the country.

Russia decided to expel the British diplomats in a tit-for-tat response to the UK's expulsion of 23 of its diplomats.

Former Russian spy Sergei Skripal and his daughter Yulia remain in a critical but stable condition after the attack on 4 March.

UK Prime Minister Theresa May said the Salisbury poisoning was "part of a pattern of Russian aggression against Europe".

The EU said its ambassador to Russia was recalled "for consultations".

The European Council statement added: "We stand in unqualified solidarity with the United Kingdom in the face of this grave challenge to our shared security."

Mrs May briefed her counterparts on Thursday on the poisoning of the Skripals, who were found unconscious on a bench in Salisbury.

Detective Sergeant Nick Bailey, who became ill after responding to the incident, is no longer in a serious condition and has been discharged from hospital.

The prime minister set out the evidence the UK has against Russia - including the positive identification of the chemical used as a type of Novichok nerve agent and the knowledge that Russia has produced this agent within the last 10 years.

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