Ernst Wilhelm Steinitz was a German fighter pilot in the World War One, risking his life to defend the country he called home. 

Two decades later, when his own government turned on him because of his Jewish ancestry, he fled abroad, his blonde hair and blue eyes enough for him to be overlooked by Nazi border guards as he crossed into the Netherlands on his way to settle in the UK. 

When his grandson Dominic tried to reclaim the German citizenship, a right he thought was granted under German law, he was denied. 

The problem? His family wasn't Jewish enough. 

Dominic explains that under a stipulation only recently withdrawn from German law, he was excluded from restitution as his grandfather, although acting in justified fear for his life, had not technically had his rights removed – he "did not lose his German citizenship under the decree of 1941 as he was not considered sufficiently Jewish, he had only two Jewish grandparents."

The case is one of hundreds in which families have discovered loopholes in Germany's citizenship laws deny them the possibility to regain a status effectively stripped from them by Adolf Hitler's regime.

Felix Couchman, co-founder of the Article 116 Exclusions Group, a lobbying organisation made up of those who have been refused restitution, says the rejection has been like "rubbing salt into very sore wounds."

Couchman, a lawyer, notes the significant emotional toll of the process. He says for members it was a "huge dilemma to decide to apply for the German citizenship in the first place, given the horrors of the past."

Adding: "For those who overcome this, researching into their family past has in many cases stirred up strong emotions, such as seeing 'black on white' what their forebears and others went through was very traumatic. Then they had to wait in limbo before finally being told they were not eligible.”

While many trying to regain German citizenship are, like Dominic, from a Jewish background there are those whose families were persecuted by the Nazis for their political beliefs. 

Cole Henley's great-grandfather, Albert Schreiner, was a prominent German communist who led a Left-wing group that fought the Nazis before they came to power. After Hitler took control, Schreiner and his family fled, first to France then, as the Nazis approached Paris, to England and finally the US.

Applying for German citizenship following the Brexit vote, Henley found that "learning about his [Albert's] struggles, battles and principles gave me a strong sense of connection to Germany. It has also given me terrible fears of where Britain is heading."

Henley's application also failed. His mother, born in 1952, was deemed too old to be considered an applicable descendant, rightful of restitution, under German law.

"The rejection seemed primarily arbitrary. For example, my cousins could apply but I could not because our [maternal] parents were born in different years, which seemed unfair," Cole says. 

Both Henley and Dominic have joined Couchman's group. 

Named after the law they hope to change, the Article 116 Exclusions Group has been lobbying the German government over the past year. 

Several hundred strong, more than half the members are UK-based. Like Cole, many British members were galvanized to apply following the 2016 Brexit vote. The rest are dotted around the globe, including significant contingencies in the US and Australia. 

Anyone who was stripped of their citizenship by the Nazis on political, racial or religious grounds — as well as their descendants — is eligible for restoration under Article 116 of the German Basic Law. 

Many victims of Nazi Germany have received restitution via Article 116, but several stipulations in the law continue to hamper others. 

German-Jewish anthropologist, Dani Kranz, notes that when Article 116 was originally implemented in 1949, "Both bureaucrats and lawmakers, but also political actors, carried over from the Nazi era to post-war Germany. This means as well that specific tropes of thinking remained in institutions and continued institutional thinking and memories."

The group has had mixed results lobbying German lawmakers to overcome these institutional hurdles.

They have gained support from individual MPs from all major Bundestag parties, excluding the anti-migrant Alternative für Deutschland (AFD), and full party support from the Green Party, the Free Democratic Party and Die Linke (The Left). However, they are yet to get the backing of the governing parties – Chancellor Angela Merkel's Christian Democratic Union of Germany (CDU) and its junior partner, the center-Left Social Democratic Party of Germany.

Ulla Jelpke, MP for Die Linke, has been a consistent advocate for the group. "I support those people because they are descendants of Nazi persecutees," She says. 

Adding: "These people have suffered from injustice, and it is our duty to correct this injustice as much as possible." 

Social Democratic Party MP, Eva Hoegl, concurs: "It is absolutely essential that descendants of former Germans, who had to leave Germany during the Nazi era, should have the possibility to regain German citizenship on application. 

"This is and will always be part of Germany's responsibility in rehabilitating victims of the Nazi regime."

Despite being less than a year old, the group has already had some success. 

Pressure from it led to the adjustment of administrative guidelines for international naturalization applicants. Announced in August by German interior minister Horst Seehofer, the revision will do away with certain exclusions, including those against the descendants of women who were forced to emigrate after marrying non-German men. 

"Germany must face up to its historical responsibility towards those who, as the descendants of German citizens who were persecuted by the Nazis, have faced legal obstacles to citizenship," Seehofer said during the announcement. 

While Couchman and fellow organizers were pleased by this, it did not go far enough. The group is demanding a complete change to the law that will accommodate those who already live in Germany, many of whom have individually been battling for restitution for many years before the group was formed. 

"The decree was undoubtedly brought about by the hard work of a group of like-minded and affected individuals, so it is bittersweet that only some of those will be supported by this decree," says Cole. 

Couchman says Germany "only made any changes after intense pressure was put on them ... the new decrees, while representing a positive step forward, still fail to cover a number of unfair exclusions.

"Only through a change of the German Nationality Act will it be possible to do justice to the principle of reparation enshrined in the German constitution." 

In September, the Austrian parliament unanimously approved the granting of citizenship to British-Austrian victims of the Nazis and their descendants. The group now hopes Germany will follow its lead. 

Despite its growth, which is partly due to an aggressive media campaign, the group remains small. Organizing members might be distinguished in their professions – lawyers, doctors, journalists – but they are contending with nation states and their imposing bureaucracies. 

Seehofer's announcement is seen by the group as a victorious battle in a long war. Couchman, along with fellow key-organizers Isabelle Couchman and Nick Courtman, have vowed to fight on, until all those eligible have the right to German citizenship.