Ms Moore-Gilbert, an academic who was most recently a lecturer in Islamic Studies at Melbourne University, has been in Tehran's Evin prison for more than a year, having reportedly been given a 10-year sentence.

She began a hunger strike on Christmas Eve along with another jailed woman, French-Iranian academic Dr Fariba Adelkhah, in protest at their treatment.

British Iranian Nazanin Zaghari-Ratcliffe is now planning to join them in refusing food, in solidarity.

In an open letter published by supporters and confirmed by the Centre for International Research at Sciences-Po where Dr Adelkhah works, the two academics said: "We will strike on behalf of all academics and researchers across Iran and the Middle East, who like us have been unjustly imprisoned on trumped up charges and simply doing their job as researchers.

"We have been subjected to psychological torture and numerous violations of our basic human rights."

Iran maintains the women are being afforded their legal rights, and says it will not bow to a 'political smear campaign'.

Zaghari-Ratcliffe's husband is urging the Australian and British governments to "shake off the complacency of their holiday heads"

He added: It is one thing for the Iranian regime to hold innocent people hostage, it is quite another to let them die."

Australian Associated Press