Nazanin Zaghari-Ratcliffe has been summoned to an Iranian court next Monday for a new trial.
The British-Iranian, under house arrest in Tehran since being moved from jail in March due to the coronavirus pandemic, has been told to expect to return to prison, according to her husband Richard.
The charity worker is nearing the end of her current five-year sentence after being jailed on spying charges in 2016.
She has always denied the charges.
Richard Ratcliffe, said the Iranian summons came only days after British courts delayed, by six months, an imminent hearing over a legal dispute between Iran and the UK about an outstanding debt which dates back to before the 1979 revolution.