In responding to this morning’s debate on party rule changes, Jim Kennedy, the Labour national executive committee (NEC) member who moved them, shook his head in wonder: “The rules used to be the most mundane part of the conference.” He was correct to reflect that the passionate attention paid to rule changes is a sign of the newly vibrant nature of the party’s internal democracy.

One of those rule changes looks like it should have been uncontroversial in a party where anti-racism is a central value:

“No member of the party shall engage in conduct which in the opinion of the NEC is prejudicial, or in any act which in the opinion of the NEC is grossly detrimental to the party. The NEC shall take account of any codes of conduct currently in force and shall regard any incident which in their view might reasonably be seen to demonstrate hostility or prejudice based on age; disability; gender reassignment or identity; marriage and civil partnership; pregnancy and maternity; race; religion or belief; sex; or sexual orientation as prejudicial to the party; these shall include but not be limited to incidents involving racism, antisemitism, Islamophobia or otherwise racist language, sentiments, stereotypes or actions, sexual harassment, bullying or any form of intimidation towards another person on the basis of a protected characteristic as determined by the NEC, wherever it occurs, as conduct prejudicial to the party.”

To the untrained eye, the manner in which the amendment was proposed looks like a welcome example of the party coming together after a fractious series of widely publicised controversies over antisemitism. It was proposed by the Jewish Labour Movement – which represents those Jews in the party who are Zionists – but it was also endorsed by Jeremy Corbyn himself, whose relationship with Zionism is sceptical to say the least, together with Momentum, some of whose activists have been accused in the past of antisemitism.

But such is the ability of antisemitism to spark conflict in the Labour party, that the amendment has not gone unchallenged, despite the apparent consensus. Labour Party Marxists already told its members: “This is supported by the Jewish Labour Movement, which already tells you that you should probably oppose without even having to read it.” There have been calls to expel the JLM for its support for Israel, including by delegate Sara Callaway during the debate.

Leah Levane, a Jewish delegate from Hastings and Rye, whose constituency had initially put forward a different wording, reluctantly withdrew her amendment in favour of the NEC one but not without a sharply worded declaration that the Jewish Labour Movement did not speak for her. Then, in the response to the debate, Naomi Wimborne-Idrissi castigated the JLM for “running to the Daily Mail and the Telegraph with stories” before objecting to the reference in Levane’s amendment to “holding” beliefs since: “That’s thought crime, comrades, and we can’t be having it.” Wimborne-Idrissi also lauded the launch the previous evening of Jewish Voice for Labour, a group that aims to push back at what it sees as attempts to “widen” the definition of antisemitism.

The controversy over antisemitism in Labour is therefore unlikely to go away any time soon. However much the party’s rules might condemn antisemitism and enable disciplinary action against those accused of it, there is no getting around the fact that there are competing definitions of what antisemitism consists of. That Jews themselves disagree only complicates matters further.

As was argued from the platform, the amendment might help to rally Jews back to Labour in some constituencies

Nonetheless, the fact that the JLM, the NEC, Corbyn and Momentum were able to cooperate in this matter does suggest a desire to come together for the good of the party. Indeed, the JLM’s Twitter account proclaimed “help Jeremy Corbyn fight antisemitism”, a striking refutation of the accusation that the group is seeking to undermine his leadership. As Mike Katz from the JLM and Philip Cohen, a Jewish councillor from Finchley, both argued from the platform, the amendment might help to rally Jews back to Labour in some constituencies. The desire to achieve power can be a way of concentrating minds of Corbynites and Labour Zionists alike.

The amendment is another example of the tension between enabling free debate within Labour and ensuring it is a disciplined party that can win elections (the lack of Brexit debate is another). If Polly Toynbee is right and Corbyn has been transformed into a politically savvy pragmatist, then his backing of the amendment is a manifestation of this. What remains to be seen is whether those who spoke against the amendment will accept the inevitable restraint that this implies.

• Keith Kahn-Harris is a writer and sociologist based in London. He is the author of Judaism: All That Matters, Turbulent Times: The Jewish Community Today (with Ben Gidley) and Extreme Metal: Music and Culture on the Edge