An Iranian court has sentenced the British-Iranian dual national Nazanin Zaghari-Ratcliffe to a one-year jail term and banned her from leaving the country for a year after, according to her lawyer. She was found guilty of spreading propaganda against the regime, the court said, after she attended a demonstration outside the Iranian embassy in 2009 and spoke to a BBC Persian journalist at the gathering. Her lawyer, Hojjat Kermani, said an appeal was being lodged on the basis that the charges had been laid out of time. The foreign secretary Dominic Raab said the sentence was inhumane and added that he would redouble his efforts to secure her release. Zaghari-Ratcliffe has already spent five years in jail, including many months in solitary confinement, on separate spying charges. She was first arrested in April 2016 after she visited Tehran with her daughter, Gabriella, then almost two years old, to visit her parents. Her husband, Richard Ratcliffe, said he believed the one-year travel ban was sequential to the jail term, meaning his wife would not be able to leave Iran for two years. He added that she had not been summoned to prison, and was unlikely to be ordered to do so until her appeal is heard within 20 days, and a judgment issued. Ratcliffe described his wife as calm but jittery. He said he had not yet spoken to Gabriella, who is now back with him in London, about the implications of the news in detail, but she was aware of a development in her mother’s situation. He also revealed that the Foreign Office had told him on Friday that it had not raised a dossier on her torture and mental condition with the Iranians for fear of offending them. He says he warned the Foreign Office last September that unless it took a harder line, her release was likely to be delayed until 2023. The second set of charges were announced last year and her trial was held more than a month ago. She was told she would be given the sentence within seven working days, but a delay followed. Her lawyers argued no new evidence was produced in the second trial that had not been available to the Iranian security services at the first trial. Boris Johnson, the UK prime minister, said the British government “would be working very hard” to secure her release. “I don’t think it is right that Nazanin should be sentenced to any more time in jail,” he said. “I think it is wrong she is there in the first place, and we will be working very hard to secure her release from Iran, her ability to return to her family here in the UK, just as we work for all dual national cases in Iran. “The government will not stop, we will redouble our efforts, and we are working with our American friends on the issue as well.” The UK, France and Germany are in talks, being held in Vienna, alongside the US, Russia and China to negotiate a way for the US and Iran to return to full compliance with the nuclear deal signed by Iran in 2015. Ratcliffe said it was not clear if the Americans and Europeans viewed the release of dual nationals as a hoped-for byproduct of the Vienna talks, alongside the lifting of sanctions, or were instead prepared to make it an explicit demand. Partly for fear of complicating the already fraught nuclear talks, due to recommence on Tuesday, the west has been wary of raising human rights issues in this arena. Another British-Iranian dual national, who according to the Foreign Office does not want publicity, is due to face charges on Wednesday, as is a German-Iranian dual national. Tulip Siddiq, Zaghari-Ratcliffe’s local MP, said: “This is a terrible blow for Nazanin and her family, who have been hoping and praying that she would soon be free to come home. It is devastating to see Nazanin once again being abusively used as a bargaining chip. “We’ve been told the government has been working behind the scenes to secure Nazanin’s release. These efforts have clearly failed and we deserve an urgent explanation from minsters about what has happened.” The foreign secretary, Dominic Raab, said: “This is a totally inhumane and wholly unjustified decision. We continue to call on Iran to release Nazanin immediately so she can return to her family in the UK. We continue to do all we can to support her.” Her sentencing comes as the deep rifts between the Iranian foreign ministry and the Islamic Revolutionary Guard Corps over control and conduct of foreign policy had been laid bare by the leak of a lengthy taped interview given by the Iranian foreign minister Javad Zarif.