Nazanin Zaghari-Ratcliffe’s husband, Richard Ratcliffe, branded the sentence “a punishment without a crime”, and said she was struggling most with being separated from their two-year-old daughter Gabriella.
The 37-year-old charity worker from Hampstead, north London, has already been detained for more than 150 days after being accused of plotting to overthrow the Iranian regime.
A five-year sentence was handed down by the Revolutionary Court on Tuesday – the day after the UK and Iran resumed closer diplomatic ties.
Mr Ratcliffe said his wife had begged him to do “whatever you can” to secure her release from Evin prison, and revealed that she had suffered hair and weight loss as a result of the ordeal.
She was arrested at Imam Khomeini airport on 3 April as she attempted to return to the UK following a holiday with her daughter.
The couple’s phone call on Friday, when she told him of the jail term, was only their third conversation since her detention, Mr Ratcliffe said.
He told Sky News his wife had spoken of her sadness at being separated from her daughter for over a fifth of her child’s life, describing her treatment as “so hard and harsh”.
Gabriella turned two in June without her mother or father, and is being cared for by her grandparents in Tehran after having had her passport confiscated.
Mrs Zaghari-Ratclfife had asked: “Why am I still here?” during their conversation, her husband said.
Her husband said the timing of her sentencing was “no coincidence”, suggesting that it was an attempt to prevent an improvement in relations between Iran and the UK.
Mr Ratcliffe’s in-laws had urged him not to make news of the sentencing public, out of a “great sincerity and fear” of making her situation worse, he said.
Shadow foreign secretary Emily Thornberry has demanded that the government take more urgent action, saying her case “beggars belief”.
She said: “it is grotesque that a young mother should be removed from her baby to serve as a pawn in prisoner swaps.
“The Iranian government needs to drop this case and return Nazanin to her family here in Britain, and her own government needs to demand that action now.”
Mr Ratcliffe has said it can only help that the Government has put political pressure on the Iranian government.
The Foreign Office said it was deeply concerned by the reports and that the case would be raised by Prime Minister Theresa May and Foreign Secretary Boris Johnson with their counterparts in Iran.
News Source SkyNews