Nazanin Zaghari-Ratcliffe has been taken to court in Iran, where her trial was adjourned before she could put forward a defence, according to her local MP.

Tulip Siddiq said no British officials were present at the hearing on Monday, despite repeated requests from Mrs Zaghari-Ratcliffe’s family to formally assert the UK’s right to consular access.

The 42-year-old British-Iranian woman has been detained in Iran since 2016 when she was sentenced to five years in prison over allegations, which she denies, of plotting to overthrow the Iranian government.

Last week, Mrs Zaghari-Ratcliffe, who has been under house arrest since March due to the coronavirus crisis, was told she must attend court on Monday and prepare to return to prison following the hearing.

She is now back under house arrest at her parents’ home in Tehran, with no date for the next court hearing, according to the Labour MP for Hampstead and Kilburn.

It is understood that UK authorities did formally request to attend the hearing, but access was denied as Iran does not recognise dual nationality.

“It is hard to imagine the mental torture that being repeatedly threatened with a return to prison causes, and this awful situation is now being dragged out once again,” Ms Siddiq said.

Nazanin Zaghari-Ratcliffe detained
Richard Ratcliffe has asked the Foreign Secretary to formally assert the UK’s right to consular access (Stefan Rousseau/PA)

“Nazanin’s safety is my top priority, and I urge the UK Government to make it their top priority too by stepping up consular support and efforts to secure her release.”

Her husband, Richard Ratcliffe, spoke with Foreign Secretary Dominic Raab last week, following the court summons.

Mr Raab said on Friday that Iran will undermine efforts to improve its relations with the UK if the mother-of-one is returned to prison.

Following the hearing on Monday, the Foreign Secretary called the decision to begin a new case against Mrs Zaghari-Ratcliffe “appalling”.

“The Iranian authorities have put an intolerable burden on Nazanin and her family,” he said in a statement.

“I am relieved she remains on temporary release, but she needs to be returned home to her family. We continue to make this clear in the strongest terms.”

On Thursday, Iranian ambassador Hamid Baeidinejad was summoned to a meeting at the Foreign, Commonwealth & Development Office (FCDO), where he was told of the UK’s “grave concern” at the development.

FCDO director-general for the Middle East Thomas Drew said the ambassador was told the move was “unjustified and unacceptable, and is causing an enormous amount of distress”, a spokesman said.

It has been claimed that Mrs Zaghari-Ratcliffe is being held to force the UK to settle on a debt dating back to the 1970s when the then-shah of Iran paid the UK £400 million for 1,500 Chieftain tanks.

Nazanin Zaghari-Ratcliffe detained
The mother-of-one has been out of prison on furlough but under house arrest in Tehran since March (Family handout/PA)

After he was toppled in 1979, the UK refused to deliver the tanks to the new Islamic republic and kept the money, despite British courts accepting it should be repaid.

The Iranian authorities have denied any link between the debt and the imprisonment.

Mrs Zaghari-Ratcliffe was arrested at Tehran’s Imam Khomeini airport while travelling to show her young daughter, Gabriella, to her parents in April 2016.

She was later afforded diplomatic protection by the UK Government, which argues that she is innocent and that her treatment by Iran failed to meet obligations under international law.