Boris Johnson is due to meet Nazanin Zaghari-Ratcliffe’s husband to discuss efforts to secure the release of the British-Iranian mother who is in prison in Tehran.

Richard Ratcliffe has secured a face-to-face meeting with the Prime Minister on Thursday as he seeks to increase the pressure to free his wife, who has been detained since 2016.

On Tuesday, Mr Ratcliffe was meeting the UK’s ambassador to Iran, Rob Macaire, who has had his own brush with the Iranian justice system amid soaring tensions.

Richard Ratcliffe with his daughter Gabriella
Richard Ratcliffe with his daughter Gabriella (Victoria Jones/PA)

Fears have increased over Ms Zaghari-Ratcliffe’s chances of freedom after the US killed top Iranian general Qassem Soleimani, causing spiralling tensions in the Middle East.

Downing Street confirmed the PM – who has faced persistent criticism over his handling of the charity worker’s case – would meet Mr Ratcliffe at No 10.

Mr Ratcliffe previously said he wanted to meet Mr Johnson to hear him signal “this is a priority” and that he is “personally taking interest” in the case.

Kate Allen, director of Amnesty International UK, said the meeting was a “welcome step”, adding: “Given recent deeply unsettling events in Iran, it’s now all the more important that Boris Johnson provides proper reassurances to the family that real and concerted efforts are being made at the highest levels to secure Nazanin’s release.”

Ms Zaghari-Ratcliffe, a 40-year-old mother from London, is serving a five-year sentence after being arrested during a holiday with her daughter and accused of spying.

Nazanin Zaghari-Ratcliffe with her daughter Gabriella
Nazanin Zaghari-Ratcliffe with her daughter Gabriella (The Free Nazanin campaign/PA)

Her family and the UK Government have always maintained her innocence and she has been given diplomatic protection by the Foreign Office.

Diplomatic protection is a little-used mechanism by which the Government can try to help individuals it believes have been wronged by another state.

It means Ms Zaghari-Ratcliffe’s treatment by Iran is a formal state issue and recognises that the legal proceedings brought against her failed to meet international standards.

Mr Johnson has been persistently criticised for wrongly claiming, when he was foreign secretary, that she was training journalists at the time of her arrest.

Four days later she was summoned to an unscheduled court hearing during which Mr Johnson’s comments were cited as proof she was engaged in “propaganda against the regime”.

“We’ve repeatedly called on No10 to prioritise Nazanin’s plight as well as the other UK-Iranian dual nationals unfairly jailed in Iran, so this is a welcome step from the prime minister.

“Given recent deeply unsettling events in Iran, it’s now all the more important that Boris Johnson provides proper reassurances to the family that real and concerted efforts are being made at the highest levels to secure Nazanin’s release.”

Ms Zaghari-Ratcliffe is among as many as five people with dual British-Iranian nationality, or with UK connections, believed to be in prison in Iran.

Boris Johnson
Boris Johnson (Henry Nicholls/PA)

Mr Macaire returned to London for talks after being labelled “persona non grata” by Iran’s judiciary, and hardline protesters burned an effigy of the diplomat.

He had been arrested and briefly detained after attending a vigil for the 176 people, including four Britons, who were killed when Iran accidentally downed a Ukrainian jet amid spiralling tension.

There are some hopes that diplomatic tensions could ease between London and Tehran if a long-running £400 million dispute is settled in the Court of Appeal this week.

Iran’s ambassador to the UK, Hamid Baeidinejad, tweeted that if a portion of the debt is assigned to Tehran then it will mean “the legal process of the case is coming to an end and there will be no excuse for default” from the Government.

The sum has been outstanding since pre-revolutionary Iran paid the UK for 1,500 Chieftain tanks in the 1970s.

The deal was cancelled after the Shah of Iran was deposed in 1979, but Britain has refused to heed Iran’s demands to hand back the money.