Hundreds of Satmar rabbis have demonstrated outside the Swiss embassy in London in protest at plans to desecrate a medieval Jewish cemetery.
They claimed the expansion of the Kunsthaus fine art museum in Zurich threatened to damage the burial ground.
Jewish communities in New York, Tel Aviv and Switzerland have met Swiss representatives to argue against the work.
The Commission for the Preservation of American Heritage Abroad has also appealed for excavation work at the site to be halted.
Opponents of the work say the expansion of the Kunsthaus venue could be completed in a way that would allow the Jewish graves to remain in place.
A Satmar spokesman said: “The impending uprooting of this cemetery is especially hurtful, given the history and sanctity of the cemetery, which dates back over 600 years and is known to be the resting place of great sages.”
It is believed that Rabbi Moshe of Zurich, one of the authors of the Tosefot commentary on the Talmud, is buried there.
Rabbi David Niederman, president of the United Jewish Organisations (UJO) of Williamsburg and North Brooklyn – which arranged the London protest – said: “The Jewish community at large simply cannot remain silent in face of this holy site being destroyed.”