Poisoned Russian opposition leader Alexei Navalny’s condition has improved, allowing doctors to take him out of an induced coma, the German hospital treating him said on Monday. Mr Navalny, a high-profile critic of the Kremlin, was flown to Germany last month after becoming ill on August 20 on a domestic flight in Russia. German chemical weapons experts say tests show Mr Navalny, 44, was poisoned with a Soviet-era nerve agent, prompting the German government last week to demand that Russia investigate the case. “The patient has been removed from his medically induced coma and is being weaned off mechanical ventilation,” Berlin’s Charite hospital said. “He is responding to verbal stimuli. It remains too early to gauge the potential long-term effects of his severe poisoning.” It said the decision to make Mr Navalny’s condition public was made in consultation with his wife. He had been in an induced coma in the Berlin hospital since being transferred to Germany on August 22 for treatment. German Chancellor Angela Merkel’s office indicated that she might be willing to rethink the controversial German-Russian gas pipeline project in a sign of Berlin’s growing frustration with Moscow’s stonewalling about the case. German authorities said last week that tests showed “proof without doubt” that Mr Navalny was poisoned with a chemical nerve agent from the novichok group. British authorities identified the Soviet-era novichok as the poison used on former Russian spy Sergei Skripal and his daughter in England in 2018. Russia has denied that the Kremlin was involved in poisoning Mr Navalny and accused Germany of failing to provide evidence about the poisoning that it requested in late August. On Monday, the UK’s Foreign, Commonwealth and Development Office said it had summoned the Russian ambassador to the UK to face questions over the incident. “The UK government registered its deep concern with the Russian government about the poisoning of Alexei Navalny with a chemical nerve agent from the novichok group,” the office said. “The Foreign Secretary has made it clear that it is absolutely unacceptable that a banned chemical weapon has been used, and that violence has again been directed against a leading Russian opposition figure. "There is a case here for Russia to answer. This took place on Russian soil, against a Russian citizen. "They have international obligations to uphold. This is nothing short of an attack against the rules-based international system that keeps our societies safe. “Russia needs to conduct a full, transparent criminal investigation into Mr Navalny’s poisoning. We will work with our partners to hold the perpetrators to account.” German Foreign Minister Heiko Maas said on Sunday that the Russian reaction could determine whether Berlin changes its long-standing backing for the Nord Stream 2 pipeline. The pipeline would bring Russian gas to Germany under the Baltic Sea, bypassing Ukraine. “The chancellor also believes that it’s wrong to rule anything out,” her spokesman, Steffen Seibert said on Monday. Previously, Mrs Merkel had insisted on “decoupling” the Navalny case from the pipeline project, which the US strongly opposes. In August, three US Republican senators threatened sanctions against the operator of a Baltic Sea port in Mrs Merkel’s constituency, which is a staging post for ships involved in building Nord Stream 2. Mr Seibert made it clear that Berlin wanted answers soon. “I can’t express a clear, time-limited expectation, except that we are certainly not talking about months or the end of the year,” he said. German diplomats rejected the Russian suggestion that Berlin was to blame for any delay in investigating the case. They said Mr Navalny was first treated for suspected poisoning in the Siberian city of Omsk on August 20. “All evidence, witnesses, traces and so forth are in the place where the crime was committed, presumably somewhere in Siberia,” German Foreign Ministry spokesman Christofer Burger said. The co-leader of Germany’s opposition Green party, Robert Habeck, called on the government to take a stronger stance and “bury” the pipeline project. The project “divides Europe, it is economically nonsensical and oversized, and it is wrong in security policy terms", Mr Habeck said. Completing it “would mean that Russia can do what it wants. This signal must not be sent". Mikhail Ulyanov, the Russian envoy to international organisations in Vienna, voiced suspicions about the timing of demands to link the pipeline with the Navalny case. “Suspicious coincidence of Navalny case and the final stage of Nord Stream 2 construction, which some states desperately want to be closed," Mr Ulyanov tweeted. "I am not fond of conspiracy theories but it is obvious that the tragic events with Navalny are very timely and helpful for opponents of NS2."