Carol singers gathered outside 10 Downing Street in solidarity with a West Hampstead mum trapped in Iran.

People showed their support for Nazanin Zaghari-Ratcliffe, 42, who was arrested in Tehran in 2016 after being accused of plotting to overthrow the Iranian government – charges long refuted.

Husband Richard Ratcliffe said at the event on Monday (December 20) that he is touched by “the unexpected kindness of people” who have stood by his campaign.

“This is our third prime minister we’ve been singing to and hopefully we will not be here again next year," he told the crowd.

Ham & High: Gabriella and Richard Ratcliffe at Carols for NazaninGabriella and Richard Ratcliffe at Carols for Nazanin (Image: Polly Hancock)

Speaking at the event, human rights lawyer Margaret Owen condemned government inaction and criticized prime minister Boris Johnson, saying: “He will be enjoying Christmas in Chequers with his children, and yet he denies Nazanin and the other hostages Christmas with their families here."

Last month, Ms Owen completed a six-day hunger strike in solidarity with Richard Ratcliffe, who went without food for three weeks in a protest outside the Foreign Office.

Feminist volunteer organisation FiLiA has launched a campaign of relay hunger strikes, with women encouraged to sign up for 24-hour fasts. The group has signed up 500 people.

Organiser Freya Papworth said she was astounded by the scale of support the campaign has received: “Our biggest hope is that we get to say to these women: 'Thank you, but we don't need you, Nazanin is home.'”

Ham & High: Pragna Patel, Margaret Owen OBE and Freya Papworth from the feminist organisation FiLiA, which is co-ordinating 24 hour hunger strikes in support of Nazanin Zaghari-RatcliffePragna Patel, Margaret Owen OBE and Freya Papworth from the feminist organisation FiLiA, which is co-ordinating 24 hour hunger strikes in support of Nazanin Zaghari-Ratcliffe (Image: Polly Hancock)

Nazanin's detention has been linked to a £400 million debt owed by Britain to Iran. Foreign secretary Liz Truss told an event at Chatham House earlier this month that it is a “legitimate debt” that the government wants to pay.

She said the government was going to “work night and day to prevent the Iranian regime from ever getting a nuclear weapon” but also said it was working to “resolve the issue” over the debt – relating to a cancelled order for 1,500 Chieftain tanks dating back to the 1970s.

Sanctions remain in place and Ms Truss said: “But of course, there are lots of issues, which I’m sure you are quite well aware of.”

She said: “I’m also pressing for the return of our unfairly detained British nationals, including Nazanin.”

Ham & High: Gabriella and Richard Ratcliffe at Carols for NazaninGabriella and Richard Ratcliffe at Carols for Nazanin (Image: Polly Hancock)