LONDON (Reuters) - Britain will consider what further action to take on Russia over the case of Kremlin critic Alexei Navalny, who fell ill after German doctors said he was poisoned by nerve agent Novichok, foreign minister Dominic Raab said on Tuesday. “We haven’t yet attributed (it) to the FSB (security service) or the Russian state, but I think there is an incredibly strong case for Moscow to answer,” Raab told a parliamentary committee. “We’ll have to consider what further action we take,” he said, adding Britain would look carefully at conclusions from a report by the Organisation for the Prohibition of Chemical Weapons (OPCW).