For the past decade, the American Reform movement has been engaged in a re-evaluation of traditional rituals, from Shabbat to kashrut. There is more Hebrew in the services, more yarmulkes, more interest in using mitzvot to bring holiness to the mundane.

But now, a small group of mainly older Reform Jews is resisting. They say this growing interest in ritual observance is a betrayal of Reform’s original rationalist approach to faith, and is putting the movement on the slippery slope towards Orthodoxy.

In 2008, a handful of rabbis committed to this classical Reform vision set up the Society of Classical Reform Judaism, to promote the traditions of American Reform Judaism, including services conducted in English and accompanied by choir and organ.

The group had a kind of formal coming out last month at the Union for Reform Judaism’s biennial convention in Toronto, where its executive director, Rabbi Howard Berman, led two workshops. It is the first time Classical Reform has been given such a public forum at the gathering.

“One of the most common misperceptions we face is that Classical Reform Judaism is a phase of history that is now over,” Rabbi Berman said. “We want to re-assert our place at the Reform table.”

Fifty Reform rabbis and cantors sit on the society’s advisory board, and the group works with three dozen North American congregations. Some of them are “explicitly Classical Reform”, Rabbi Berman said. The others are “mainstream Reform” who occasionally run separate services along Classical Reform lines to serve mainly older congregants, “who are often pushed aside, marginalised” by guitar-playing, kippah-wearing, younger Reform rabbis.

Much of the appeal of Classical Reform is the organ music, the use of English, a “High Church” approach to worship that society leaders contrast to what they call the “Conservative-lite” practice of “Warm Reform”.

But there is a strong intellectual component too. Dr Michael Meyer, professor of Jewish history at Hebrew Union College in Cincinnati, is not a follower of Classical Reform, but does appreciate it, he says, as a check on the movement’s growing piety.

As God-talk becomes more prevalent in Reform circles, and younger Reform Jews return from summer camp and Israel programmes speaking Hebrew and talking about kashrut, Reform’s emphasis on the prophetic vision of social justice and universal brotherhood is in danger of becoming lost.

“We have come to a point in Reform where we stress the personal, emotional connection more than is perhaps sustainable,” Dr Meyer said. “There is a place for reason in religion, and sometimes in Reform Judaism today we don’t give that enough attention.”