The husband of a British-Iranian woman detained in Iran since 2016 is to stage a protest outside the country’s embassy with their six-year-old daughter.

Nazanin Zaghari-Ratcliffe, 42, has completed a near five-year sentence in the Islamic Republic over widely refuted allegations of plotting to overthrow its government. She strongly denies the charges.

The mother-of-one finished the latter part of her sentence under house arrest due to Covid-19 and had her ankle tag removed on Sunday.

But she must still appear before an Iranian court in a week’s time to face new charges. The Guardian reports the new allegations – long threatened by Iranian authorities – concern Mrs Zaghari-Ratcliffe’s involvement in propaganda activity against Iran, including attending a 2009 demonstration outside its embassy in London, and speaking to BBC Persian.

Her husband Richard Ratcliffe – who has long campaigned for her freedom – will demonstrate with the couple’s daughter Gabriella and his wife’s brother Mohamed outside the Iranian embassy in Knightsbridge from around midday on Monday.

He will deliver a 60,000-signature Amnesty International petition to the embassy calling for his wife’s immediate release.

Mr Ratcliffe called it a “watershed” moment, saying: “If you’d asked me when we first started campaigning with Amnesty to bring Nazanin home that five years later we’d still be knocking on the door of the Iranian embassy, still waiting for them to ever open it and explain what’s going on, then I would have been horrified.”

He earlier said he was “grateful” for the “strong words” of Foreign Secretary Dominic Raab, who condemned the “cruel and intolerable” treatment of Mrs Zaghari-Ratcliffe and called for her swift return to the UK.

Prime Minister Boris Johnson has urged Iran to release her “permanently”, adding her “continued confinement remains totally unacceptable”.

Mrs Zaghari-Ratcliffe, of north London, was arrested at Tehran’s Imam Khomeini Airport while taking Gabriella to see her parents in April 2016.

Nazanin Zaghari-Ratcliffe detained
Nazanin Zaghari-Ratcliffe served a near five-year jail term (Nazanin Zaghari-Ratcliffe/PA)

The charity worker, who was employed by the Thomson Reuters Foundation at the time of her arrest, strongly denies the charges and civil rights groups say she was jailed with no evidence and her trial was unfair.

The UK has been locked in a high-profile diplomatic tussle over Mrs Zaghari-Ratcliffe’s detention, which has seen her held in solitary confinement and undergo hunger strikes.

Rupert Skilbeck, director of the Redress legal campaigning group, told the PA news agency the “cumulative effect” of her confinement over the past half decade “crosses that threshold into torture” and warned over long-term psychological effects.

The UK Government has afforded her diplomatic protection, arguing she is innocent and that her treatment by Iran failed to meet obligations under international law.

Mrs Zaghari-Ratcliffe has been used as a political pawn, according to Nobel Laureate and Iranian human rights lawyer Shirin Ebadi.

Commentators have linked a long-standing debt running into hundreds of millions of pounds as central to the case, which has been dubbed “hostage diplomacy” by former foreign secretary Jeremy Hunt.

The UK is thought to owe Iran as much as £400 million over the non-delivery of tanks in 1979, with the shipment stopped because of the Islamic revolution.

Mrs Zaghari-Ratcliffe’s constituency MP Tulip Siddiq (Hampstead and Kilburn) has connected the debt with the case.

She told the PA news agency last month: “My constituent’s life is basically a bargaining chip because she’s not being set free because we haven’t fulfilled our responsibility of paying the debt.

“If there’s some movement on that I reckon Nazanin’s chances are increased.”