Richard Ratcliffe fears Nazanin Zaghari-Ratcliffe, who was arrested in 2016 while on holiday with her daughter Gabriella, could be taken back to court “within a week or so” on a resurrected charge of spreading propaganda against the regime.
Mr Ratcliffe believes a case is being opened against her as Foreign Secretary Boris Johnson prepares to meet his French and German counterparts and EU high representative Federica Mogherini for talks on Iran in Brussels.
It comes after members of her family visited prosecutors for an update on her case, according to Mr Ratcliffe, who says she is being used as a “bargaining chip”.
He said she told him of the development in a 5.30am phone call on May 14, and added: “I have no clue why they have started all this nonsense again. They know Boris is coming.
“Please take me out of this, please. My parents have had enough. I want my daughter back. She needs both of us. So tell the world. Enough of this nonsense.”
Mrs Zaghari-Ratcliffe was arrested during a visit to show her baby daughter Gabriella to her parents.
The 39-year-old mother, from Hampstead, north London, is serving a five-year sentence over allegations, which she denies, of plotting to overthrow the Tehran government.
She said in a statement released through the campaign to free her: “Sometimes when I come back from the visit with Gabriella, after saying goodbye to her, I feel like I cannot live without her, I want to go back and hold her.
“She kisses me so hard. It is hard to say goodbye to her. She blows kisses all the way as she goes up the stairs, and everyone stands there watching.
“After the news of a new court case again, yesterday was one of those days. I kept thinking, how did I survive without her for 26 months?”
Mr Ratcliffe said: “The UK needs to do better by British Iranians - at the moment it is failing to protect them.
“UK policy is not making it safe for British citizens. Iranian policy is not making it safe for Iranian citizens.”
He urged Mr Johnson to have “Nazanin and the cases of all the other British citizens taken at the top of his priority list” during his meetings in Brussels.
He said: “A deal that protects people is one that can work. Failure to make it safe for people to be free from being held arbitrarily, free to visit their families in peace, will make any deal impossible to sustain. Governments should not downplay the significance of this fact.
“We hope the Foreign Secretary visits Iran as soon as possible, for the safety of all British citizens. We hope this time a way can be found for him not to return again empty-handed.”