The European Union has recalled its ambassador from Moscow after the bloc’s 27 other leaders backed Theresa May’s claim that the Kremlin was “highly likely” to be responsible for this month’s nerve agent attack in Salisbury.

In a joint statement after midnight Brussels time the EU leaders said there was “no plausible alternative explanation” for the use of novichok in Salisbury other than its deployment by the Russian government.

Dmitry Peskov, Vladimir Putin’s spokesman, said on Friday that Russia “doesn’t understand” the EU’s decision, and said Moscow would need to study the exact measures being taken by the bloc before it could respond.

Ms May urged leaders at a dinner of the European Council in Brussels to go further than their foreign ministers had on Monday, when the bloc said that they took the assessment of Russian responsibility “extremely seriously”.

The EU said its ambassador had been recalled “for consultations” following the incident. It is also understood that Ireland, France, Estonia, Poland, Latvia and Lithuania are considering the expulsion of Russian diplomats, following the UK’s decision to expel 23 of them, including alleged undeclared intelligence officers.

The Kremlin said the UK was forcing its allies to take “confrontational steps” over the incident. Russia denies any involvement in the poisoning.

Mr Peskov said: “We don’t know what info the UK had when it discussed with EU colleagues. We don’t understand it.

“Russia has not had the opportunity to receive a diagnosis [on the Skripals]. Regarding the EU decision, we are unhappy with ‘highly likely’ formulations. Russia categorically has nothing to do with the Skripal [poisoning].”

Speaking at the summit on Friday, Taoiseach Leo Varadkar said: “What we’ll now consider in the coming days is whether we want to take individual action relating to Russian diplomats in Ireland, bearing in mind what the UK did was to expel 23 diplomats, who they did not believe were diplomats, they were agents.

“We would have to do a security assessment before we did that. We’re not just going to randomly expel people who are genuine diplomats.”

The Prime Minister, who was due to leave for London after the Thursday dinner, is now also attending part of the Friday portion of the summit, after a discussion on trade with the US was delayed to wait a response from the Trump administration.

Speaking on the doorstep of the summit in the small hours of the morning after the dinner, Ms May said: “We’ve had a very full discussion on Russia at this EU Council and I welcome the fact that the EU Council has agreed with the UK Government’s assessment that it is highly likely that Russia was responsible for the attempted murder that took place on the streets of Salisbury, and that there is no plausible alternative explanation.

“Russia, and the threat that Russia poses, respects no borders and that is a threat to our values and it is right that here in the EU Council we are standing together to uphold those values. I’m going to be back here tomorrow morning at the EU Council when we have a very important discussion on trade.”

Former Russian intelligence officer Sergei Skripal and his daughter, Yulia, remain in a critical condition following the 4 March attack in Salisbury.

The joint statement by the European Council says: “The European Council condemns in the strongest possible terms the recent attack in Salisbury, expresses its deepest sympathies to all whose lives have been threatened and lends its support to the ongoing investigation.

Skripal attack aftermath – in pictures Show all 15 1 /15 Skripal attack aftermath – in pictures Skripal attack aftermath – in pictures Scene of attack Members of the emergency services in hazard suits fix the tent over the bench where Sergei and Yulia Skripal were found unconscious on a park bench in Salisbury in March 2018. Getty Skripal attack aftermath – in pictures Victim - Sergei Skripal The retired Russian colonel and former double agent for MI6 was in a critical condition in hospital for more than two months after being exposed to novichok in Salisbury. He was given refuge in the UK after being jailed in Moscow for treason. Mr Skripal came to Britain as part of a high-profile “spy swap” in 2010 in which four men were exchanged for ten Russian "sleeper agents" in the US. In this image he is speaking to his lawyer from behind bars in Moscow in 2006. AP Skripal attack aftermath – in pictures Victim - Yulia Skripal Yulia Skripal was struck down by a novichok poison alongside her father Sergei. Facebook Skripal attack aftermath – in pictures Scene of attack A police officer stands guard outside a branch of the Italian chain restaurant Zizzi where the pair dined at before falling ill. It was boarded off whilst investigators worked on the building and later found traces of the chemical weapon within it. AFP/Getty Skripal attack aftermath – in pictures Scene of attack Large areas of central Salisbury were cordoned off by police following the discovery of the Skripals. Traces of nerve agent were also found in The Mill pub. PA Skripal attack aftermath – in pictures Victim - Nick Bailey Detective Sergeant Nick Bailey, rushed to the aid of the Russian ex-spy and his daughter who were targeted with a nerve agent. He was hospitalized after aiding them and didn't leave until three weeks after the attack. Wiltshire Police/Rex Skripal attack aftermath – in pictures Police investigation - Skripal’s home Police believe they were poisoned at home, and detectives found the highest concentration of novichok on the front door of Mr Skripal’s house. Getty Skripal attack aftermath – in pictures Theresa May visits scene of attack Britain's Prime Minister Theresa May spokes with Wiltshire Police's Chief Constable Kier Pritchard near where the Skripal's were found. Britain expelled 23 Russian diplomats over the nerve agent poisoning and suspended high-level contacts, including for the World Cup on March 14. Theresa May told parliament that Russia had failed to respond to her demand for an explanation on how a Soviet-designed chemical, Novichok, was used in Salisbury. AFP/Getty Skripal attack aftermath – in pictures Skripal days before attack Sergei Skripal days before he was exposed to Novichok, that has left him fighting for life. ITV News Skripal attack aftermath – in pictures Police investigation - military involvement British soldiers were deployed soon after the attack to help a counter-terrorism investigation into the nerve agent attack. One of the places they were asked to help out with was Skripal's home and it's surrounding. They were asked to remove a vehicle connected to the agent attack in Salisbury, from a residential street in Gillingham. AFP/Getty Skripal attack aftermath – in pictures Police investigation Personnel in protective coveralls and breathing equipment cover an ambulance with a tarpaulin at the Salisbury District Hospital. AFP/Getty Skripal attack aftermath – in pictures Police investigation The investigation extended to the grave of Sergei Skripal's son Alexander in London Road cemetery. Getty Skripal attack aftermath – in pictures Police investigation The Counter Terrorism Policing Network requested assistance from the military to remove a number of vehicles and objects from Salisbury. EPA Skripal attack aftermath – in pictures Home Secretary visits scene of attack Home Secretary Amber Rudd visited the scene of the nerve agent attack at the Maltings shopping centre on 9 March. Getty Skripal attack aftermath – in pictures Yulia Skripal speaks for the first time Yulia Skripal, speaking for the first time, said she felt lucky to have survived the nerve agent attack in Salisbury which left her fighting for life. Ms Skripal said her life had been “turned upside down” by the assassination attempt. But the Russian national added she hoped to return to her homeland one day, despite the Kremlin being blamed for the attack. Reuters

“It agrees with the UK Government’s assessment that it is highly likely that the Russian Federation is responsible and that there is no plausible alternative explanation. We stand in unqualified solidarity with the United Kingdom in the face of this grave challenge to our shared security.

“The use of chemical weapons, including the use of any toxic chemicals as weapons under any circumstances, is completely unacceptable, must be systematically and rigorously condemned and constitutes a security threat to us all.