Germany has paid tribute to Claus von Stauffenberg and others who sought to assassinate Adolf Hitler 75 years ago, a plot that was recognised only belatedly but which a resurgent far-right is now seeking to expropriate.

In the attempt on 20 July 1944, Stauffenberg and other high-ranking conspirators within the Nazi regime sought to kill Hitler at his Wolf's Lair headquarters.

The plot was to seize control of the regime and make peace with Western allies to end World War II. But Hitler survived the bombing and Stauffenberg and other key figures in Operation Valkyrie were executed the same night.

At a ceremony in Berlin today, where new German Bundeswehr soldiers were sworn in, Chancellor Angela Merkel underlined the importance of remembering this anniversary at a time when far-right forces are once again gaining ground with their nationalist line.

It was important to "keep the conspirators' memories alive", as well as those of all Germans who resisted the Nazis, because their acts could be seen as a "warning" for today's society, she said.

"They remind us that we have to be vigilant. They remind us that we must resolutely fight far-right extremism, anti-Semitism and racism in all their different forms.

"There are moments when disobedience can be a duty," Ms Merkel said.

The right to resist is explicitly enshrined in Germany's post-war constitution, which would not exist in its current form without people such as Stauffenberg, the chancellor said.

"Even today, there is still a lot of incomprehension and ill-ease" about the assassination attempt, Ms Merkel said, not least because Stauffenberg was himself an army officer.

The prison where Hitler's attackers were executed

Stauffenberg and his Operation Valkyrie was brought to the big screen in 2008 when Tom Cruise played the former count as a hero who led an act of resistance against Hitler and his deadly regime.

But at home, the verdict on Stauffenberg is more mixed, with some critics branding him a committed Nazi who only changed sides when it was clear that Hitler was going to lose the war.

In the aftermath of World War II, some in then West Germany - where former Nazis had assumed key positions in the new democratic country - also viewed him as a traitor.

Kurt Salterberg, a soldier at Wolf's Lair when the attempt took place, recalled that "the troops' condemnation of Stauffenberg was unanimous" then.

"We thought he was a coward who didn't use a pistol but a bomb so that he could get out unscathed," Salterberg told the Frankfurter Allgemeine Zeitung in an interview.

Portraits of members of the World War II German resistance, including Claus von Stauffenberg

In fact, hundreds of resistance fighters who were executed over their involvement in the plot were also only given due recognition in 2009, when their murders were finally branded an injustice by the court, said Johannes Tuchel, who heads the German Resistance Memorial, in a commentary for TAZ daily.

With the lingering ambiguity on Stauffenberg's legacy, far-right forces, including the AfD party whose leader has downplayed the Nazi era as a "speck of birdpoo", have claimed to be the inheritors of the heroic act.

The anti-immigrant Alternative for Germany, which is now the biggest opposition party in parliament, has repeatedly used the word "resistance" to characterise its battle against mainstream parties today.

"The calculation of the new right, the AfD and the (far-right movement) Identitarians is clear: to portray themselves as victims of the "chancellor-dictator", to see a 'dictatorship' in a free country, and to gain legitimacy for their own political activities by making the reference to political activities," said Mr Tuchel.

That is "historically wrong and inappropriate. Resistance against Nazism stands for freedom, rule of law and tolerance," he added.

Stauffenberg's granddaughter, Sophie von Bechtolsheim, has also said it was "indecent" for a party to claim to be the rightful heirs of his legacy.

More than seven decades on, Salterberg too sounded the same warning against the right-wing extremists.

"The youth of today must not be led astray by political demagogues, and must show civil courage. That's why remembrance of the conspirators is important.

"Stauffenberg was seen then as a traitor, but today I know that he sacrificed his life for Germany and a better world."