Germany says it is discussing with EU and NATO partners a suitable response to Russia, following the announcement by German doctors Wednesday that opposition leader and Kremlin critic Alexei Navalny was poisoned by a military-grade nerve agency called Novichok. Navalny was airlifted to a Berlin hospital two days after becoming violently ill after boarding a plane in eastern Russia two weeks ago. Moscow says it has not received any evidence from Germany over the accusation. Henry Ridgwell reports