The husband of Nazanin Zaghari-Ratcliffe, a British-Iranian woman jailed in Tehran, expressed his joy on Friday at the return of their young daughter to Britain but also concern at the impact it would have on his wife. "It's a very happy day," Richard Ratcliffe told a press conference as he cuddled five-year-old Gabriella on his lap.

She returned on Thursday night from Iran, where she has lived with her grandparents since Zaghari-Ratcliffe's arrest during a visit to family in Tehran in April 2016. But Ratcliffe said it was a bittersweet moment as his wife was "distraught" at the departure of her daughter, who she has seen regularly during her detention on sedition charges.

The little girl's visits to Evin prison had been "an important lifeline". "It was one of the things she really didn't want to happen, for her daughter to leave and for her to still be stuck in prison," he told reporters in parliament. Ratcliffe called on Prime Minister Boris Johnson to secure the return of his wife, who campaigners say is a victim of a diplomatic standoff between London and Tehran.

"We have been caught in the middle of a government fight," he said, adding: "Their failure to solve it has had a huge human cost on our family." Zaghari-Ratcliffe was sentenced to five years in jail for allegedly trying to topple the Iranian government, which she denies.

Her case has unfolded amid escalating tensions between Tehran and the West, particularly the United States and Britain. But Ratcliffe believes it is particularly linked to the failure of London to return £400 million ($500 million, 450 million euros) owed to Tehran for a 1970s tank deal.

The deal was blocked after the 1979 Islamic Revolution but Britain kept the money. Its transfer is now complicated by EU and US sanctions over Iran's nuclear programme. Zaghari-Ratcliffe's local MP, Tulip Siddiq, urged London to unblock the money so they could start discussing her release.

Ratcliffe has also accused Johnson of making his wife's case worse by mistakenly stating, when he was foreign minister, that Zaghari-Ratcliffe had been training journalists. At the time of her arrest, she was a project manager with the Thomson Reuters Foundation, the media group's philanthropic arm. Ratcliffe said Iran's Islamic Revolutionary Guard Corps sought to block Gabriella's return, but the British embassy and the Iranian foreign minister intervened.

Afterwards, he said the Guard had threatened his wife again with court action linked to Johnson's comments. Ratcliffe is now seeking a new meeting with the premier, saying: "He hasn't yet delivered for us. He has a chance."

Copyright Agence France-Presse, 2019