The husband of locked-up British citizen Nazanin Zaghari-Ratcliffe is seeking urgent updates from the Foreign Secretary after Iranian authorities signalled her release had been sanctioned.
Richard Ratcliffe said it was not clear what was delaying a return to the UK for his wife, a British-Iranian dual citizen serving a five-year prison sentence after being convicted of spying charges in 2016.
He was joined by supporters outside the Foreign and Commonwealth Office in Westminster today, with the group laying 707 pebbles and rocks to represent each day Mrs Zaghari-Ratcliffe had been imprisoned for.
"Part of the point today is to make the slightly pointed message to the Foreign Secretary - 'please, this has gone on long enough'," Mr Ratcliffe told ITV News.
"This week there was a statement by the Iranian ambassador to London, which was a lot more positive, saying that they were looking for a solution."
Mr Ratcliffe said the head of the prison his wife was being held stated he had approved her release.
Mrs Zaghari-Ratcliffe, a charity worker for the Thomson Reuters Foundation, denies the charges and maintains she was in Iran to introduce her young daughter Gabriella to her parents.
A Foreign Office spokeswoman said: "We will continue to approach each case in a way that we judge is most likely to secure the outcome we all want.
"Therefore we will not be providing a running commentary on every twist and turn."