British Prime Minister Theresa May said Monday it was “highly likely” that Moscow was behind the poisoning of a Russian former double agent. It is highly likely that Russia was responsible for the act against Sergei and (his daughter) Yulia Skripal,” May said, telling British lawmakers the military-grade nerve agent used in the attack was of a type developed by Russia. The prime minister gave Moscow until the end of Tuesday to disclose details of its development of the Novichok nerve agents programme to the Organisation for the Prohibition of Chemical Weapons.