Wikipedia says that the working definition of antisemitism (also called the International Holocaust Remembrance Alliance definition of antisemitism or IHRA definition) is a non-legally binding statement on what antisemitism is which was adopted by the IHRA Plenary (consisting of representatives from 31 countries) in Bucharest, Romania, on 26 May 2016.

The statement reads:

Antisemitism is a certain perception of Jews, which may be expressed as hatred toward Jews. Rhetorical and physical manifestations of antisemitism are directed toward Jewish or non-Jewish individuals and/or their property, toward Jewish community institutions and religious facilities.

Accompanying the working definition, but of disputed status, are 11 illustrative examples whose purpose is described as guiding the IHRA in its work, seven of which relate to Israel.

For example, one of them is

Denying the Jewish people their right to self-determination, e.g., by claiming that the existence of a State of Israel is a racist endeavor.

The IHRA definition has been criticised by some academics who say that it stifles free speech relating to criticism of Israeli actions and policies. High-profile controversies took place in the United Kingdom in 2011 within the University and College Union and within the Labour Party in 2018. The definition has been contested for weaknesses that critics say lend themselves to abuse, for obstructing campaigning for the rights of Palestinians and for being too vague.

One of the original drafters, Kenneth S. Stern, has opposed the “weaponizing” of the definition on college campuses in ways that might suppress and limit free speech.

In April 2023 the Guardian reported that more than 100 Israeli and international civil society organisations have asked the United Nations to reject a controversial definition of antisemitism because it is being “misused” to protect Israel from legitimate criticism. They wrote to the UN Secretary-General:

Adoption of the definition by governments and institutions is often framed as an essential step in efforts to combat antisemitism. In practice, however, the IHRA definition has often been used to wrongly label criticism of Israel as antisemitic, and thus chill and sometimes suppress, non-violent protest, activism and speech critical of Israel and/or Zionism, including in the US and Europe.

More information

https://en.wikipedia.org/wiki/Working_definition_of_antisemitism

The full text of the IHRA definition of antisemitism