Two Russian nationals have been named as the key suspects in the Salisbury novichok poisoning incident from March this year.
Scotland Yard says there is enough evidence to charge Alexander Petrov and Ruslan Boshirov - believed to be aliases - with the attack which left former Russian spy Sergei Skripal and his daughter Yulia fighting for their lives.
It is believed that the two men are officers from the Russian military intelligence service, also known as the GRU.
Traces of novichok were found in their East London hotel room, ahead of travelling to Salisbury in early March.
Speaking in the Commons, prime minister Theresa May insisted: “This was not a rogue operation. It was almost certainly also approved outside the GRU at a senior level of the Russian state.”
Mrs May stressed that if the two men traveled outside of Russia again, UK forces would take every possible step to detain and extradite them to face justice in the UK.
She added: “We were right to act against the Russian State in the way we did [in March] and we are right now to step up our efforts against the GRU.
“We will not tolerate such barbaric acts against our country.”