Oscar-winning actress Emma Thompson led a small protest Saturday demanding the British government do more to help a woman jailed in Iran, accusing Boris Johnson of making her situation worse.

Thompson said the foreign secretary should "get on a plane" to Tehran as she joined supporters of Nazanin Zaghari-Ratcliffe, including her husband Richard Ratcliffe, in the couple's neighbourhood of Hampstead in north-west London.

"We are a net of compassion and love for Nazanin and her family. This is what we human beings do best -- in stark contrast to the bunch of angry molecules bumping around in Westminster," the actress said.

"If I can get out of bed with pneumonia to support a horribly abused member of our community then our foreign secretary can get on a plane and go to Iran and deal with the problem he's so seriously exacerbated."

Zaghari-Ratcliffe, a British-Iranian citizen, was arrested at Tehran airport on April 3, 2016, after visiting relatives with her young daughter.

She was sentenced to five years in jail for sedition. Then last month authorities presented extra charges, and she will appear in court on December 10 accused of spreading propaganda.

Johnson was accused of jeopardising her defence by saying she was training journalists before she was arrested -- something her employer, the Thomson Reuters Foundation (TRF), and her family have strongly denied.

The foreign secretary later clarified his remarks, saying it was clear that she was only on holiday. He is expected to raise her case when he makes an official visit to Iran in the coming weeks.

Thompson, a mother of two who won a best actress Oscar for "Howard's End", is supporting a "mother's open letter" calling on Tehran to free Zaghari-Ratcliffe so she can be reunited with her daughter.

Gabriella, now three, had her British passport confiscated and has since been living with her grandparents in Iran.

Source: AFP