Donald Trump is poised to expel more than 20 Russian diplomats from the US in the wake of the poisoning of a former spy in Salisbury.

In a significant boost for Theresa May, the US President could take action as soon as Monday following the attempted murder of Sergei Skripal and his daughter, Yulia.

Britain has thrown out 23 Russians that the Government says were using diplomatic cover to spy on the UK. Up to European 20 nations, including Germany, France, Poland, Lithuania, Latvia and the Czech Republic are now considering following Britain’s lead.

The European Union has also recalled its ambassador from Moscow following the poisoning. A US Government spokesman said: “[We are considering] a range of options in response to Russia’s outrageous actions in the UK, both to demonstrate solidarity with our ally and to hold Russia accountable for its clear breach of international norms and agreements.”