Labour's ruling National Executive Committee has approved a new code of conduct on anti-Semitism.
The code, drawn up in the wake of intense controversy over allegations of prejudice which saw Jewish groups protest outside Parliament earlier this year, states explicitly that "anti-Semitism is racism. It is unacceptable in our party and in wider society".
But it insists that criticism of the state of Israel and its policies should not automatically be regarded as anti-Semitic, and makes clear that even "contentious" comments on this issue "will not be treated as anti-Semitism unless accompanied by specific anti-Semitic content... or by other evidence of anti-Semitic intent".
"The party will encourage considered and respectful debate on these difficult topics, but will not tolerate name-calling and abuse," says the document.
The new code of conduct - drawn up in response to a key recommendation of the 2016 Chakrabarti report into anti-Semitism - endorses the working definition of anti-Semitism drawn up by the International Holocaust Remembrance Alliance (IHRA).
It includes a list of behaviours likely to be regarded as anti-Semitic derived from the IHRA's own set of examples, including calling for the killing of Jews, making allegations about a Jewish conspiracy or control of the media and economy, Holocaust denial or the "blood libel".
But the Labour list is likely to spark further controversy, as it omits four behaviours identified as anti-Semitic by the IHRA, including:
- Accusing Jewish people of being more loyal to Israel than their home country;
- Claiming that Israel's existence as a state is a racist endeavour;
- Requiring higher standards of behaviour from Israel than other nations; and
- Comparing contemporary Israeli policies to those of the Nazis.
The Labour document - obtained by LBC radio - states that it is not always obvious whether particular words or actions are anti-Semitic, with "particular difficulty" surrounding the relationship between anti-Semitism and criticism of the state of Israel.
It says that the party "is clear that the Jewish people have the same right to self-determination as any other people" and that to deny that right is a form of anti-Semitism.
But it says that debate on the circumstances of the foundation of the Israeli state and its impact on the Palestinian people "forms a legitimate part of modern political discourse".
However, it stresses that "care must be taken when dealing with these topics", insisting it is wrong to hold Jewish people generally responsible for the actions of the Israeli state or to demand that they are more vociferous than others in condemning its acts.
The document states that it is not anti-Semitic to refer to Zionism or Zionists in debate about the situation in the Middle East, but warns that it is "not permissible" to use Zionist or "zio" as "a code word for Jew".
Although the list of banned anti-Semitic behaviours does not include the act of accusing Jews of being more loyal to Israel and to worldwide Jewish interests than their home states, the code states that it is "wrong" to do so.
And it advises Labour members that the use of Hitler, Nazi and Holocaust metaphors and comparisons in discussion about Israel and the Palestinians "carries a strong risk of being regarded as prejudicial or grossly detrimental to the party".