If the JC had an award for Letter of the Year (and why not?), my 2020 shortlist would be headed by last week’s missive from a Rabbi Guy Hall, who revealed that he had been evicted from a Liberal rabbinic conference 27 years ago for “officiating mixed-faith couples under a chupah”. Picture the scene: defrocked like Captain Dreyfus and wearing a condemned man’s black kippah, Rabbi Hall is dragged to the Liberal door and ordered to darken its step no more.

This is life on the front line, a rabbi laying down his canonicals rather than giving up a devoutly held new article of faith. Guy Hall, who is now an “independent Liberal European Rabbi specializing in Jewish and Interfaith life-cycle ceremonies”, goes on in his letter to decide that “a couple where one is Jewish and one is not should be able to have a Jewish ceremony without prejudice or discrimination”. To do otherwise, he warns, is to risk being accused of racism.’

Now that’s a prize letter. Still, 27 years is a long time ago and Liberal Judaism has moved on, which is more than most progressive movements manage to do. Look at the Liberal Democrats (no relation). They still believe in the United Nations and the redistribution of wealth.

Unlike the LibDems, LibJews march boldly ahead. A shofar-blasted decree by LJ’s interim director Rabbi Charley Baginsky will now permit Jews to join beneath the chupah with non-Jews in an act of holy matrimony. There are strings attached — both parties must commit “to keeping a Jewish home” — but in general this is a leap forward of circuit-breaking magnitude. “Our movement prides itself on its commitment to diversity and equality,” says Rabbi Baginsky; and so must we all. Pride is one thing, practice another.

Seen in the light of all that is holy, marrying non-Jews beneath a chupah is a glass-shattering breach of tradition. The chupah is a gazebo for two single Jews who accept the blessings of kiddushin and nisuin, a pair of Aramaic concepts that combine the sanctity of Jewish affinity with the inviolability of contract law.

Open up the ceremony to a partner who is not Jewish and the chupah has as much holiness as a factory-reject colander.

Don’t get me wrong. I’m all in favour of Liberal Judaism and I appreciate that it approached this fateful decision over 27 years with a deliberation that makes the London Bet Din appear positively bionic.

What I love about Liberal leaders is their desire to stay in step with the religious consensus even as they step ever further out of line. Their display of solidarity can be heartening. When an eruv was mooted in our area and the council called for citizens’ opinions, first up with a fiery endorsement for this Sabbath refinement was the Liberal Jewish Synagogue, an institution which had dispensed with Sabbath laws while Victoria was still Queen. But this was a Jewish cause and the LibJews were keen to be our allies. Which is why it distresses me now to see them heading off the Jewish map.

Down the years, it has been assumed that the Libs quietly married “mixed-faith couples” without much fuss, a “mixed-faith couple” being (in my understanding) a union in which one partner is confused about being Jewish and the other about being gentile. The LibJews also led the line in sanctifying same-sex unions, acting as a beacon for the rest of non-Orthodoxy. All well and good.

But a chupah for non-Jews is a step too far. The Pope wouldn’t marry a non-Catholic and, while the Church of England accommodates non-Anglican brides and grooms, it continues to require them to endorse a “Christian understanding of marriage.” They maintain a tougher line than our Liberals.

These are testing issues. Every faith is losing souls to outsourcing. According to the last IJPR survey in 2016, one in four British Jews marries or cohabits with a non-Jew. Most who step out, stay out.

On the plus side, the wedding market is huge — quarter of a million events every year in the UK — and Liberal Judaism could now pitch for a much larger slice. There is no end to the number of gentiles who want a chupah. They have seen Goodfellas, Fiddler on the Roof and Private Benjamin. They watch Friday Night Dinner on Channel 4 and, even though no-one on the show is actually Jewish, they can’t get enough of that banter. Where better to experience it than under a chupah — so long as there is none of the snip, dip and mumble-some-Hebrew involved with actual conversion to Judaism.

So now you don’t have to be Jewish to go under a chupah? Announce it in Hello magazine. They’ll come queueing round Lords like ticketless Aussie fans on Test match Saturday.