The husband of jailed British-Iranian mother Nazanin Zaghari-Ratcliffe has revealed his despair after confirming his unwell wife will embark on a hunger strike.

Richard Ratcliffe told HuffPost UK: “She has felt she has to do something to show enough is enough, this has gone on too long.

“And this time I have not been able to talk her out of it.”

Zaghari-Ratcliffe and fellow inmate and human rights activist Narges Mohammadi announced the strike in a joint letter written from Tehran’s notorious Evin prison, where they are both being held.

Both women say they have planned a three-day strike, but will continue until their demands are met.

Ratcliffe, who confirmed his wife is being blocked from having medical treatment for lumps in her breasts, as well as neurological and psychiatric care, says he hopes the strike will last no longer.

In a translation of the letter provided to HuffPost UK, the two women ask: “This is a serious question … Does this not risk endangering lives to abruptly stop the medication that has been prescribed for treatment by physicians for a long period of time, or to prevent transferring us for necessary specialist treatment? Is such an attitude consistent with human laws and practices?” 

Zaghari-Ratcliffe spent her 40th birthday on Boxing Day in prison as her husband revealed she feared she would be kept incarcerated for so long she would be unable to have a much longed-for second child. 

Saturday marked 1,000 days since she was first arrested at Tehran’s Imam Khomeini airport on April 3 2016. 

The charity worker, who lived in Hampstead in north London, was sentenced to five years in jail after being accused of spying, a charge she strongly denies.

Her four-year-old daughter Gabriella has been staying with family in Iran since Zaghari-Ratcliffe, who works for the Thomson Reuters Foundation, was detained.

Ratcliffe has mounted a high-profile campaign for his wife’s release, branding her detention a “travesty of justice”.