Iran has claimed the UK’s move to grant “diplomatic protection” to Nazanin Zaghari-Ratcliffe flouts international law.
Foreign Secretary Jeremy Hunt invoked the rarely-used diplomatic device in response to Iran’s treatment of the dual national, who has been held since 2016 on spying charges.
But Tehran refuses to acknowledge the British-Iranian mother’s dual nationality and said the UK’s actions were illegal.
Mrs Zaghari-Ratcliffe’s husband Richard said he hoped Mr Hunt’s move would lead to a resolution to her case within months.
“It changes the status for Nazanin’s case,” Mr Ratcliffe told BBC Radio 4’s Today.
“Now it’s also the British Government’s case and all the injustices that happen to Nazanin are effectively injustices against the British Government.”
Suggesting the move might provide “a route to solving this case”, Mr Ratcliffe said: “Probably the first things are to get a doctor in, then we’ve talked about doing stuff at the UN, then maybe summoning the ambassador.
“You can’t jump straight into legal action, there are a whole series of things that legally you need to do first before you are entitled to, and that’s months away. Hopefully we are not months away from a solution.”
Mr Ratcliffe said it would now be more difficult for Iran to turn down UK requests for visits to Mrs Zaghari-Ratcliffe in prison to check her condition.
He said his wife’s health was “obviously not in a great position, but I’m not sure how bad”.
But hopes of a breakthrough were dealt a blow by Iran’s ambassador to the UK Hamid Baeidinejad who rejected the Foreign Office announcement.
He said governments could only offer diplomatic protection for their own nationals and the UK was “acutely aware” that “Iran does not recognise dual nationality”.
“Irrespective of UK residency, Ms Zaghari thus remains Iranian,” he said.
Mr Hunt responded: “Well, I would expect some kind of negative reaction from Iran.
“All I would say to them is that we have really done everything possible.”
He told BBC Radio 4’s Today that there had been three specific tests before he acted “First of all, the commission of an internationally wrongful act, secondly, the exhaustion of what are called local remedies, and thirdly, what’s called proof of nationality for which we had to conclude that she is predominantly British, which addresses, I think, the dual nationality issue.”
While Mr Hunt acknowledged the move was unlikely to be a “magic wand” that secures her immediate release, he said it escalated the UK’s response to the situation.
The Foreign Secretary said Tehran’s actions had been “totally wrong” and that no state was entitled to use innocent individuals as “pawns for diplomatic leverage”.
“This represents formal recognition by the British Government that her treatment fails to meet Iran’s obligations under international law and elevates it to a formal state-to-state issue,” he said.
Effectively it represents the right of states to raise the treatment of their nationals by other states and to call on them to account for their actions on the international stage.
It is distinct from diplomatic immunity, which covers the status of accredited diplomats.
While it does not automatically dictate any particular course of action, the Foreign Office has indicated it will take the steps it believes are most likely to secure the goal of Mrs Zaghari-Ratcliffe’s release.
Mrs Zaghari-Ratcliffe, a charity worker with the Thomson Reuters Foundation, was arrested in April 2016 at Tehran airport as she was returning home to London with her then 22-month-old daughter, Gabriella, following a family visit.
She was subsequently sentenced to five years’ imprisonment, despite strenuously denying the charges against her, while Gabriella remains in the country cared for by family.
Repeated calls for her release by the British Government – including a direct appeal by Theresa May to Iranian president Hassan Rouhani during last year’s UN general assembly in New York – have failed to produce results.
Mr Ratcliffe has previously said his wife was told by judges in court that her case related to an unpaid £400 million debt the UK owes to Iran in relation to the purchase of Chieftain tanks in the 1970s.
In January, she went on hunger strike for three days saying the Iranian prison authorities had refused her treatment for a series of medical conditions, including lumps in her breasts, severe neck pain, and numbness in her arms and legs.