UK says would respond 'robustly' if a state behind ex-spy collapse

Foreign Secretary Boris Johnson warned on Tuesday that Britain would respond "robustly" if it emerged that a state was behind the "disturbing" collapse of a former Russian double agent in England.

Johnson confirmed to MPs that Sergei Skripal and his daughter Yulia were found unconscious on Sunday, adding: "Should evidence emerge that implies state responsibility then Her Majesty's government will respond appropriately and robustly."