Efraim Zuroff, director of the Nazi-hunting center in Jerusalem, called the commemoration planned Thursday in the northern town of Limbazi "absolutely disgusting and a terrible insult to the victims of the Holocaust in Latvia."
On July 4, 1941 – three days after Nazi forces took control of Riga – Latvian partisans took up arms against the occupying Soviet Red Army and drove them out of Limbazi.
German forces then swept in, rounding up and killing all the town's Jews, or an estimated 100 people out of a total population of 2,800.
"This is old-fashioned anti-Semitism with a very strong nationalist flavor. You can draw a direct line from the anti-Semitism of the 1930s to this anti-Semitism today," Zuroff told AFP.
University of Latvia historian Agnes Bedike has said that Latvian partisans may have begun arresting Jews before the Nazis took control of the town.
Thursday's event is organized by nationalist groups including Visu Latvijai! (All for Latvia!), a junior partner in the Baltic state's three-party coalition government.
A public invitation to the ceremony says the battle "protected many townspeople from destruction so that new generations could be raised" but makes no mention of the grim fate of its Jewish residents.
The nationalists also organize controversial annual ceremonies in March honoring members of the Latvian Legion, two local divisions of the Waffen-SS.
Lativan Foreign Minister Edgars Rinkevics told AFP Wednesday that the Limbazi event was "unacceptable".
He said he would attend a ceremony Thursday at the Riga synagogue honoring the around 300 Jews who died inside when the Nazis set it on fire on July 4, 1941.