Every Monday night, I tune in to Salford City Radio's Jewish Hour. The contents of this lightly choreographed magazine programme always provide food for thought, and the edition of June 23 proved no exception. Shoehorned into its last few minutes was a discussion involving Andrew Chandler, chair of the Manchester Liberal Jewish Community.

Liberal Judaism, Chandler explained, was "a radical political kind of Judaism." It was "completely egalitarian." Men and women sat together - naturally. Jewish identity could be transmitted through the male as well as the female lines. Naturally. Observance of halacha, listeners were assured, was far from being "a compulsory activity." All this was highly predictable.

But then, in the very last moments of the interview, Chandler admitted something truly shocking: not only were barmitzvahs making a comeback, but more generally (it appears) Liberal Jews were becoming "more traditional." My ghast was flabbered!

After all, Liberal Judaism was conceived, 110 or so years ago, as a revolt against any-thing and everything that was "traditional." That's what its founders (the gentleman scholar Claude Montefiore and his female devotee Lily Montagu) meant it to be. Out went ritual. Out went references to Zion. Out went old-fashioned ideas about Shabbat and kashrut. For the Liberals, Jewish identity was defined primarily in terms of the rejection of everything that Orthodoxy stood for.

Judaism was reduced to nothing more than a set of moral principles. Montefiore himself explained that as far as he and his disciples were concerned, to be a good Jew amounted to no more than to be a good citizen, meaning "righteousness in action and truthfulness of the heart." Who could possibly quarrel with that?

I suspect a return to halachah for the Liberals soon

But within this noble-sounding formulation there was, and remains, a systemic flaw. In rejecting the divinity of the Torah, Liberal Jews actually found themselves lacking in moral certainty. What does "righteousness in action" mean, if it is not grounded in divinely-ordained precepts?

The answer has been supplied most recently by the current chief executive of Liberal Judaism, Rabbi Danny Rich. Referring to Liberal Judaism's March 2011 decision to "update" its liturgy to accommodate marriage for same-sex couples, Rich explained that "the evidence suggests that on this matter Liberal Jewish thought and policy were in tune with the changing public mood …"

Are we therefore to conclude that it is in fact "the changing public mood" (rather than - say - God Almighty) that triggers modifications to Liberal-Jewish theology? It would appear that we do. If so, Liberal Jews are treading a very slippery slope. Over the past two decades we have certainly witnessed changes in public attitudes towards sexual deviancy. But suppose "the public mood" took, or seemed likely to take, a different turn? Would Liberal Judaism then meekly and obediently revise its dogma to suit the whim of the moment? If (God forbid!) "the public mood" turned against brit milah, what would be Liberal Judaism's response?

But this worship of "the public mood" is not confined to Liberal Judaism. Writing in the Independent (October 9 2012), Rabbi Dr Jonathan Romain (a former chair of the Assembly of Rabbis of the Movement for Reform Judaism) proclaimed that "anyone who takes sacred religious texts literally needs to move on with the times... the Bible is not the literal word of God, but the inspiration of God, as perceived by people of that era and subject to the limitations of the period. It therefore has to constantly adapt according to new knowledge and new insights."

Where morality is concerned, people need certainty. Reliance on "the public mood" – or moving on "with the times" – removes that assurance: the firm footing of dogma is replaced by the shifting sands of current fads and fashions.

I suspect that this explains why we are apparently witnessing the beginnings of a return to halachah within the Mancunian chapter of the Liberal Jewish movement. For the founders of Liberal Judaism this represents an uncomfortable defeat. For Judaism it represents a striking victory.