Nazanin Zaghari-Ratcliffe’s furlough has been extended “until a decision has been made over her clemency”.

The West Hampstead woman’s time away from Iran’s Evin Prison had been set to expire on May 20, but husband Richard has announced it will now continue pending the much-awaited – and delayed – decision on the application Nazanin has made for clemency.

This could be as soon as Saturday May 23.

Nazanin has been held in Iran for more than four years.

Richard said on Wednesday morning: “Nazanin spoke to the Prosecutors’ Office today. Her furlough from prison has again been extended - until a decision has been made on her clemency.

“She was told no decision has been made on clemency. Her father was asked to come to the Prosecutors’ Office on Saturday.”

Nazanin herself is unable to go to the Prosecutors’ Office as she is forced to war an ankle tag and is under effective house arrest.

Nazanin’s local MP, Tulip Siddiq (Lab, Hampstead and Kilburn), responded to the news, too. She said: “This uncertainty is causing her and her family unimaginable stress. The government must step up efforts to make sure her furlough is made permanent.”

Another to comment was Belsize councillor and former MEP Cllr Luisa Porritt (Lib Dem) who said: “This is a huge relief, but we must not rest until Nazanin is freed. She must be granted clemency. The Foreign Office as well as our EU partners should be doing all they can to push for that outcome.”

Amnesty International UK’s director Kate Allen was critical of the “games” she argued the Iranian authorities were playing with Nazanin and her family.

She said: “Another period of this ‘conditional liberty’ is far better than outright jail, but we’re worried that the Iranian authorities are still playing games with Nazanin and her family.

“In Evin Prison, Nazanin was a prisoner of conscience - confined to her parents’ house in Tehran, Nazanin is still a prisoner of conscience.

“Nazanin was convicted after a deeply unfair trial, and she should never have been behind bars at all.”

In response to the many candles lit in solidarity with Nazanin, Richard added: “Thank you everyone who has lit candles for Nazanin in the past few days, or sent their best wishes. We are grateful for all your care.”

Earlier this week, the UK ambassador to Iran declined to visit Nazanin, who is staying at her parents’ Tehran home.

A foreign office spokesperson said: “We are in contact with Mrs Zaghari-Ratcliffe and her family and will continue to make decisions in line with what we believe will produce the best outcome.”