Boris Johnson defends remarks on Russian role in novichok case

UK foreign secretary tries to clarify apparent claim that Russia was behind nerve agent attackBoris Johnson has for the first time defended his apparent claim that Porton Down scientists had told him Russia was responsible for deploying a military grade nerve agent to poison Sergei Skripal and his daughter Yulia in Salisbury last month.Making the first defence of this claim since Porton Down scientists said they could only describe the agent as novichok, but not ascertain its country of origin,