The moment of opportunity to secure the permanent release of Nazanin Zaghari-Ratcliffe from jail in Iran “is almost gone”, her husband has said.

The British-Iranian mother-of-one is hoping to be updated on Saturday on the progress of a bid for clemency but her husband Richard Ratcliffe said it feels like “momentum has stalled”.

Mrs Zaghari-Ratcliffe had been in Iran’s notorious Evin prison since 2016 but was released on furlough on March 17 as the Covid-19 pandemic swept through the country.

Her family were hopeful that she might be permanently released as part of an amnesty for 3,000 prisoners at the end of Ramadan which was announced by the country’s supreme leader.

It has felt for a while like momentum has stalled, and that the moment of opportunity is now almost gone.

But more than two weeks after Eid, her husband told the PA news agency: “The moment of opportunity is now almost gone.”

Mr Ratcliffe said he believed his wife’s clemency is being blocked by Iran’s Revolutionary Guard despite her case having the support of the country’s judiciary.

He told PA: “We should be getting an update from the prosecutor’s office tomorrow, though in light of the games over the past couple of weeks, (we) are not holding our breath.”

He added: “Nazanin has asked to speak to the Foreign Secretary to find out just how the UK is getting her home.

“It has felt for a while like momentum has stalled, and that the moment of opportunity is now almost gone.”

Mrs Zaghari-Ratcliffe was arrested at Tehran’s Imam Khomeini airport while travelling with her young daughter, Gabriella, to meet her parents in April 2016.

She was sentenced to five years in prison over allegations of plotting to overthrow the Tehran government.

She has been afforded diplomatic protection by the UK Government, which states that she is innocent and that her treatment by Iran failed to meet obligations under international law.