Nazanin Zaghari-Ratcliffe's family have said they are on the "cusp of potentially good news" as they await a decision on whether she will be granted clemency.
The British-Iranian mother-of-one was freed from a Tehran prison on March 17 as part of the Iranian response to the Covid-19 pandemic.
Her temporary release from Evin jail was further extended last week pending a decision on whether to pardon her.
Speaking to ITV's Good Morning Britain on Tuesday, her husband, Richard Ratcliffe, said she could hear that decision on Wednesday.
"We are on the cusp of potentially good news," he said.
"On the weekend, the supreme leader of Iran announced there was going to be over 3,000 people being pardoned because of Eid at the end of Ramadan.
"Nazanin's lawyer was being brought down in front of the prosecutor's office tomorrow to get a decision on her clemency. So she could be on that list, we don't know yet."
Mr Ratcliffe said legally his wife should be on the list "because she meets all the criteria", adding that the family is "hopeful".
However, he added: "I think there is a possibility we will find out on Wednesday, there's a chance we will find out in the next couple of weeks, and if it doesn't happen in the next couple of weeks we should presume it hasn't happened.
"Part of me needs to keep preparing me for when it all falls apart and she is put back in prison and we need to keep negotiating."
Mrs Zaghari-Ratcliffe was arrested at Tehran's Imam Khomeini Airport while taking her young daughter to see her parents in April 2016.
She was sentenced to five years in prison, accused of plotting to overthrow the Iranian government, which she denies.
She was later afforded diplomatic protection by the UK Government, which argues that she is innocent and that her treatment by Iran failed to meet obligations under international law.