The husband of Nazanin Zaghari-Ratcliffe has told Boris Johnson to stop “getting distracted” in the fight to release the mother-of-one from an Iranian jail, as she prepares to go on another hunger strike.

The dual British-Iranian citizen has been imprisoned in Tehran since 2016, when she was arrested and accused of spying while visiting family.

Her husband, Richard Ratcliffe, has accused the UK of “enabling the abuse of British citizens” and said the Government “needs to take a much more robust stand against Iranian hostage-taking”.

He said: “If President Trump can get Americans home with all the baggage there, then there is no earthly reason why the UK cannot.

“It is a question of priorities, and the Prime Minister not getting distracted again.”

Ms Zaghari-Ratcliffe, 41, is due to go on hunger strike on New Year’s Eve and New Year’s Day, according to Mr Ratcliffe, in support of another dual British national being held in Iran.

Kylie Moore-Gilbert, a British-Australian academic, has been imprisoned for more than a year after being sentenced to 10 years on espionage charges, and started an open-ended hunger strike before Christmas.

Kylie Moore-Gilbert
Kylie Moore-Gilbert (Australian Department for Foreign Affairs and Trade/PA)

Ms Zaghari-Ratcliffe, who also refused food on Christmas Eve in support of Ms Moore-Gilbert, told her husband on Monday: “I really can’t keep going on like this, someone needs to do something.”

Mr Ratcliffe added: “When people are desperate, a hunger strike is the only weapon people have.

“It is to get the Iranian regime to notice, but it is also to cut through the complacency of their own governments, to remind them of their promises to get things done or leave no stone unturned.”

Mr Ratcliffe earlier expressed his solidarity with Ms Moore-Gilbert.

He told The Guardian: “Five days on dry hunger strike is becoming critical, and our thoughts go out to Kylie and her family for all this ordeal.

“I hope the Australian and British governments also step up today and shake off the complacency of their holiday heads. It is one thing for the Iranian regime to hold innocent people hostage, it is quite another to let them die.”

The Foreign Office said in a statement: “We remain extremely concerned about the welfare of Mrs Zaghari-Ratcliffe and other British-Iranian dual nationals detained in Iran.

“We continue to raise her case at the highest levels, are in regular contact with her family and press Iran for her release.”