A state parliament and the memorial foundation at the Nazis' Buchenwald concentration camp both barred Björn Höcke of the anti-immigration Alternative for Germany (AfD) party from attending their commemoration ceremonies.
Höcke, a former history teacher from the AfD's right-wing fringe, had sparked outrage by labelling Berlin's central Holocaust memorial a "monument of shame in the heart of the capital" in a January 17th speech.
The AfD chairman of Thuringia state, where Buchenwald is located, also called for "a 180-degree shift in the politics of remembrance", arguing Germany was too caught up by its shame over the war and Holocaust.
Modern Germany is seen to have confronted its dark past openly and has long shied away from strong displays of patriotism.
This reluctance has been slowly fading as the last of the last generation of old Nazis and Holocaust survivors die, and the AfD has been at the forefront of those who argue Germany must become a "normal country" again.
When Höcke, 44, showed up Friday at the Thuringia state assembly for a ceremony marking International Holocaust Remembrance Day, the speaker, Christian Carius, barred him from attending.
Carius told Höcke that "his presence would be seen as a provocation", especially by Buchenwald survivors in the audience.
The AfD slammed the exclusion as "a low point in the history" of the state parliament which, it charged, "raises considerable doubts about their understanding of democracy".
The AfD, which started out as a eurosceptic party in 2013, has since shifted to mainly railing against multiculturalism, Islam and the over one million asylum seekers who arrived since 2015 under Chancellor Angela Merkel, its declared enemy.
Later on Friday, Höcke was also prohibited from entering the Buchenwald site for a wreath-laying ceremony.
"After this speech... Mr Höcke's participation in the wreath laying in the former Buchenwald concentration camp is not acceptable," its deputy head had written the previous day.
Höcke had initially vowed to show up anyway, arguing in a letter that "it is simply not up to you to decide who can participate".
French Holocaust survivor Bertrand Herz, 86, had also spoken out, saying that "the survivors of Nazi barbarism and the relatives of those murdered cannot allow the importance of the Holocaust to be relativized and the memory of the victims to be degraded."
Holocaust Remembrance Day marks the January 27th 1945 liberation of the Auschwitz-Birkenau death camp in Nazi-occupied Poland by Soviet troops.
The day honours the memory of the six million European Jews and the hundreds of thousands of other victims of the Nazi genocide, including Poles, Roma, Soviet prisoners of war and homosexuals.
Germany, in a solemn parliamentary ceremony, marked the day with a tribute to the 300,000 ill and disabled people killed under the Nazis' "euthanasia" programme, who are often seen as the era's forgotten victims.
Parliament speaker Norbert Lammert said the programme was the first to use gas to murder those considered "unworthy of living" and served as a "trial run for the Holocaust".