A group is planning to mount a legal challenge to a “sexist and ageist” rule that denies descendants of Jewish refugees from the Nazis German citizenship because their qualifying ancestor was a woman.

The Association of Jewish Refugees said it knows of more than 100 people have either been denied, or would be denied citizenship.

Anyone who was persecuted on political, racial or religious grounds during the Nazi dictatorship, as well as their descendants, is eligible for German citizenship under Article 116 of the country's constitution.

However, anyone born before 1953 – when the law on German nationality was changed – can only receive it if their qualifying ancestor was a man. If someone is ineligible because of this, their children are ineligible as well, even if those children were born afrer 1953.

Eleanor Thom and her family applied for citizenship in 2016 but were rejected because her grandmother, Dora, left in 1938 and married a British man in November 1942 a year after the Nazis passed the Eleventh Decree law, which took citizenship from German-born Jews living outside the country – most of whom had fled just before the Second World War.

It also meant women who left Germany and married a man of different nationality after 1941 were no longer eligible and nor are their descendants.

Ms Thom told the JC: “My grandmother came here on a domestic service visa. She was a working class Jewish Berliner and she was a single mother in Germany.

“She was exiled. The alternative was imprisonment, and was unable to bring her daughter, so she lived with this loss all her life.”

Ms Thom and her 75-year-old mother applied for citizenship but, because Dora’s four daughters born between 1943 and 1951, they were not eligible.

She received a confusingly-worded rejection letter that said she could not qualify for German citizenship "from a German mother only when born before 01.01.75 (with married parents)".

It then said she could receive citizenship through a German mother born between April 1, 1953 and December 31, 1974 but this did not apply to her as her mother was born in 1943 and therefore: "She and you didn't qualify."

AJR chief executive Michael Newman said cases such as Ms Thom's were not unusual.

“The majority of people we have come across who have been rejected are descendants of female German refugees born before 1953. Clearly there is an injustice,” he said.

Mr Newman himself is likely to be rejected for citizenship under the German article 116 because his grandmother, who lived in Germany for 20 years during Nazi rule, did not have citizenship because she was originally from Poland.

“She was part of the society and left because of the Nazis. If they had not been there she would have stayed she could have had a family there,” he said.

He is part of a group of more than 30 people from the UK and abroad, who are mounting a campaign to challenge the German government over the law.

Felix Couchman, a solicitor in London, is helping the group, which is meeting on Friday to discuss the case.

“I felt sufficiently annoyed by the amount of people who I kept hearing about being rejected,” he said.

“I had no idea that it was so difficult and inherently sexist and that is wrong. My mum came across on the Kindertransport. She married my father in Britain but me and my brothers were born post 1953 so would in theory be eligible.”

He said the German nationality law was “applying the law of the 1930s. Today it seems bizarre for the country to applying an ageist and sexist law. It is wrong and it should be challenged.”