Last week authorities revealed that former British spy Sergei Skripal and his daughter Yulia, who were discovered slumped over and unconscious at a shopping mall in England, had been poisoned with an unspecified nerve agent. Today, Prime Minister Theresa May gave an update on the situation to Parliament.

“It is now clear that Mr. Skirpal and his daughter were poisoned with a military-grade nerve agent of a type developed by Russia,” May said. She continued, “Based on the positive identification of this agent by world-leading experts at the Defense Science and Technology Laboratory at Porton Down, our knowledge that Russia has previously produced this agent and would still be capable of doing so, Russia’s record of conducting state-sponsored assassinations, and our assessment that Russia views some defectors as legitimate targets for assassinations, the government has concluded that it is highly likely that Russia was responsible for the act against Sergei and Yulia Skirpal.

“Mr. Speaker there are therefore only two explanations for what happened in Salisbury on the 4th of March. Either this was a direct act by the Russian state against our country or the Russian government lost control of its potentially catastrophically damaging nerve agent and allowed it to get into the hands of others.”

May went on to say that the British Foreign Secretary had summoned the Russian ambassador to explain which of these two options it was. The UK is demanding an explanation from Russia by tomorrow.

I can already tell you what the response is going to be: “Who us? We don’t have anything to do with this.” When Russia is caught behaving badly, Russia lies. When Russia was caught bombing a caravan of food supplies in Syria it claimed the caravan must have spontaneously combusted. When Syria launched a chemical weapons attack on its own people last year, Russia claimed a bomb must have hit a secret chemical weapons factory on the ground (another lie).

The question is what the UK is going to be willing to do once they get the laughable denial from Russia. As May makes clear in this clip, the UK already took a number of steps to clamp down on Russia after the assassination of Alexander Litvinenko in 2006. Those measures are still in place but obviously didn’t prevent a repeat occurrence. In fact, as Buzzfeed reported last year, the US has linked Russia to 14 assassinations in the UK:

Earlier this week, we revealed that US spy agencies had handed the British government high-grade intelligence that the Russian whistleblower Alexander Perepilichnyy, who died in Surrey in 2012, was likely assassinated on the direct orders of the Kremlin – but the authorities sidelined that and other evidence pointing to murder, instead declaring that he had died of natural causes. Today, we can reveal that US intelligence officials suspect a further 13 people – including Berezovsky and eight members of his circle – have been assassinated on British soil by Russia’s security services or mafia groups, two forces that sometimes work in tandem.

That intelligence – based on human sources, intercepted communications, and public material gathered by US spy agencies – has been shared with Britain in relation to all 14 deaths. Yet British police have ruled out foul play in every last case.

Britain has been turning a blind eye to this for some time now. If Prime Minister May is serious about making it to stop, she’s going to have to do more than tell the Foreign Secretary to talk tough to the Russian ambassador.