Boris Johnson can make amends for his failings in Nazanin Zaghari-Ratcliffe's case by telling Iran's president "enough is enough" and securing her release, the jailed mother’s husband has said.
The British-Iranian mother is more than halfway through a five-year prison sentence that she is serving in Tehran over spying charges, allegations she vehemently denies.
The Prime Minister is due to meet President Hassan Rouhani at the United Nations General Assembly on Wednesday, at a time of heightening tensions with the Islamic republic.
Richard Ratcliffe, speaking as he travelled to New York ahead of the summit, said: "I want him to give the message that enough is enough and that Nazanin needs to come home as soon as possible.
"I don't mind how he does that but this has gone on long enough. Nazanin is at the end of her tether. We have to be clear with Iran that it's not OK to conduct hostage diplomacy."
Mr Ratcliffe said that during the Tory leadership campaign Mr Johnson "didn't take any responsibility for his mistakes" as foreign secretary.
In a much-maligned error, Mr Johnson said Ms Zaghari-Ratcliffe was in Iran "teaching people journalism" - despite her family's insistence she was there to visit relatives.
Mr Ratcliffe said: "The way he conducted Nazanin's case as foreign secretary has made it worse for her and now he has got a chance to right that and make it clear to President Rouhani that this needs to change."
On his flight to New York on Sunday, the PM told reporters he would discuss Ms Zaghari-Ratcliffe with the Iranian leader.
"I will not only be discussing Iran's actions in the region, but also the need to release not just Nazanin but others who in our view are being illegally and unfairly held in Tehran," he said.
