ANNOUNCER: This is CNN breaking news.</s>BLITZER: All right, breaking news. Only moments ago the British prime minister, Theresa May, pointed the finger directly at Moscow for a nerve agent attack on a former Russian spy. Listen to this.</s>THERESA MAY, BRITISH PRIME MINISTER: Is highly likely that Russia was responsible for the act against Sergei and Yulia Skripal. Mr. Speaker, there are therefore only two plausible 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 this potentially catastrophically damaging nerve agent and allowed it to get in the hands of others. This afternoon my right honorable friend, the foreign secretary, has summoned the Russian ambassador to the foreign and commonwealth office and asked him -- asked him to explain which of these two possibilities it is and therefore to account for how this Russian produced nerve agent could have been deployed in Salisbury against Mr. Skripal and his daughter. My right honorable friend has stated to the ambassador that the Russian Federation must immediately provide full and complete disclosure of the Novichok program to the organization for the prohibition for chemical weapons. And he has requested the Russian government's response by the end of tomorrow.</s>BLITZER: Sergei Skripal and his daughter Yulia remain in critical condition after they were found slumped on a bench in Salisbury, England, last week. Let's go to our senior international correspondent, Nick Paton Walsh. He's joining us from just outside parliament right now. So, Nick, what kind of action would the U.K., would the government of Theresa May take against Russia?</s>NICK PATON WALSH, CNN SENIOR INTERNATIONAL CORRESPONDENT:: : We don't know on that point, but we do know they're discussing it. And unless they get a full accounting of how that military grade nerve agent, and that's the word Theresa May used, calling it Novichok. I'll go into that in a moment.
Nerve Agent Attack in England