The Berlin State Opera has defended its decision to allow the Russian-born soprano Anna Netrebko to perform on its stage despite protests from people who claim she has failed to unambiguously distance herself from Vladimir Putin over the invasion of Ukraine. The singer, who has Russian and Austrian nationality, is due to appear at the Staatsoper on Friday and a further three nights in September, performing the role of Lady Macbeth in Giuseppe Verdi’s Macbeth. The Staatsoper had stopped its work with the singer over concerns about her alleged closeness to the Kremlin. But its general director, Matthias Schulz, has said in a lengthy and unusual statement that he is convinced that she has distanced herself adequately from the Putin regime and has described the war as an unprovoked invasion by Russia. Protesters are enraged, with 37,000 people having signed a petition calling for the cancellation of all four performances. Ukrainian refugees living in Berlin are to lead a demonstration outside the opera house on Unter den Linden on Friday evening, where tickets for the performance have sold out. They have previously demonstrated at venues in Wiesbaden and Baden-Baden where Netrebko has appeared. The singer has spoken of her disdain towards the protesters, denouncing them in one Instagram post as “screaming mermaids with artificial flowers in their hair” – a reference to traditional Ukrainian hair decorations. More than 100 figureheads from the worlds of culture, politics and academia have also signed a letter addressed to the Staatsoper calling for the concerts to be called off. The mayor of Berlin, the culture minister and other politicians have publicly declined invitations to attend Friday’s performance. Netrebko has been banned from other opera houses, including New York’s Metropolitan Opera, Prague’s Státní Opera and the Alexela Concert Hall in Tallinn. Defending his decision, Schulz said: “It’s important to act in a differentiated way and to distinguish between the periods before and after war broke out.” He said the singer had “clarified her position with a statement as well as through her actions in which she has distanced herself, and this should be acknowledged”. In a statement from March 2022, Netrebko said she “expressly condemned the war on Ukraine”, and insisted it was false to describe her as a supporter of Putin, saying she had met him only a handful of times, and that she was financially independent of the Russian government and paid her taxes in Austria. “My position is clear. I am not a member of any political party nor am I allied with any leader of Russia. I acknowledge and regret that past actions or statements of mine could have been misinterpreted,” she added. Dr Franziska Davies, a Munich-based eastern Europe historian and one of the signatories to the letter, accused the Staatsoper of a “morally and intellectually inadequate” attempt to justify its decision. “The reality is that Netrebko has never explicitly distanced herself from her support of the Putin regime in the past, only spoken about the fact that her behaviour was falsely interpreted, as well as styling herself as an apolitical fighter of ‘Russophobie’, to coin a Kremlin battle cry, used to delegitimise every criticism of Russia.” Netrebko’s opponents have repeatedly pointed to her audiences with Putin, including her decoration by him as a cultural figurehead, and her 2014 appearance in St Petersburg with a representative from the Russian-occupied Donbas region of Ukraine, carrying a flag of the pseudo-state Novorossiya. Netrebko’s management said the flag was unexpectedly rolled out in Netrebko’s presence and has repeatedly said she has been used as a scapegoat. Netrebko is suing the Met over its ban, which she says caused her “severe mental anguish and emotional distress, including … depression, humiliation, embarrassment, stress and anxiety, and emotional pain and suffering”. The suit alleges that the Met and its general manager, Peter Gelb, also harmed the singer’s reputation and encouraged protests against her performances. The parallels between Verdi’s opera and reality have been pointed out by myriad pundits on social media, with the programme notes describing how the Macbeths “literally walk over dead bodies” to fulfil their ambitions. Some say they see a glimmer of hope in the story’s close, in which the Macbeths “end up becoming the victims of their own lust for power”.