On the first night of Passover, a seder is held. This is a ceremonial meal which follows an order ('seder' means order). 1/
The seder is ancient and is modelled on a Greek symposium. It combines telling the Passover story, ritualised eating and prayer 2/
Outside of Israel, Jewish festive days are doubled. So two seders on two nights, traditionally. 3/
In the early 20th C, some Jewish political groups began holding a "third seder", a political event modelled on the seder 4/
This article from Tablet gives a little history of the Third Seder. tabletmag.com/jewish-life-an… 5/ 
A third seder isn't a 'seder' in the religious sense. It uses the forms of the seder for a social event with a political bent. 6/
The Jewdas seder that Jeremy Corbyn attended was a 'third seder' - a political and social event, not a religious ceremony 7/
Jewdas is a far left group. Its leaders are people who are involved in Jewish communal life. It used to run good parties 8/
Jewdas initially attracted people by pretending to be neutral. "They attack everyone!" I was told. The politics was hidden. 9/
That was never true. Jewdas always had a political agenda. Jewdas would never mock anti-Zionists, for example. 10/
Jewdas always used intensely personal attacks on people they don't like. Nasty stuff. 11/
But most of the Jews who are 'involved' in Jewdas just go for the parties and events. They're barely aware of the politics 12/
Here's where it gets complicated. One of the founders and leaders of Jewdas is on the Jewish Voice for Labour committee 13/
Jewdas will, for example, host Assad apologist Max Blumenthal despite his support for an actual onoging genocide 14/ jewdas.org/jewdas-intervi…
Blumenthal is a friend of Jewdas but the Board of Deputies is the enemy. Because supporting Israel is worse than cheering Assad 15/
...and yet, some of what Jewdas does has been clever and in dialogue with Jewish culture. It's complicated. 16/
Corbyn attending the Jewdas seder is clever. It's a move designed to force Jewish groups into internal argument 17/
On the one hand, Corbyn gets a friendly audience that pantomime-boos Jewish leaders for him. On the other, he's 'engaging' 18/
Now instead of debating Labour and antisemitism we're discussing obscure intra-communal issues that nobody understands 19/
Whoever planned this move did it to hobble the Jewish community's efforts to address Labour antisemitism. 20/
Final thought: Jewdas can be a legitimate Jewish org and still be an inappropriate partner for the Leader of the Opposition 21/
