The European Union has recalled its ambassador from Moscow after leaders on the continent threw their weight behind Theresa May's stance over the Salisbury attack.
Several EU member states were poised to announce expulsions of diplomats, in a bid to dismantle Vladimir Putin’s spy network.
Following a summit in Brussels to discuss the response to the Salisbury nerve agent attack, EU leaders gave their full-throated backing to the prime minister by adopting a statement declaring it was "highly likely Russia is responsible" for poisoning Sergei Skripal and his daughter, Yulia.
Donald Tusk, the president of the European Council, tweeted that all leaders agreed Russia's responsibility for the attack was highly likely.
In a significant point for Ms May, the statement goes further than a declaration by foreign ministers earlier this week, which avoided pinning the blame on Russia. British diplomats believe that a strong message of solidarity with the UK, from Russia’s closest European neighbours, will hit home with president Putin.
France, Poland, Estonia, Latvia and Lithuania are understood to be considering expelling Russian diplomats, as requested by the UK government, in a coordinated strike against Moscow.
On Thursday night the Dutch prime minister, Mark Rutte, said the EU ambassador to Russia was being recalled to consult with Brussels over the Salisbury attack. Mr Rutte characterised this as a "measure" rather than a formal "sanction" against Moscow.
At a dinner meeting with EU leaders in Brussels, Ms May said: "The challenge of Russia is one that will endure for years to come. As a European democracy, the UK will stand shoulder to shoulder with the EU and Nato to face these threats together. United, we will succeed."
The statement issued by the council after the summit said: “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.
"We stand in unqualified solidarity with the United Kingdom in the face of this grave challenge to our shared security."
Earlier, not all EU leaders had appeared convinced of Russia's involvement, however. The Greek prime minister, Alexis Tsipras, took a cautious line before talks with May.
"We have to express our solidarity to the UK, to the British people, but at the same time we need to investigate," Mr Tsipras said. Luxembourg's prime minister, Xavier Bettel, a former criminal lawyer, said he wanted to hear what Ms May had to say before making a decision. – Guardian Service