What would a Reform and Liberal merger mean?

If all goes to plan on Sunday, the Reform and Liberal movements will become one. Delegates from their synagogues will gather in two, simultaneous online EGMs where they will be asked to approve unification as Progressive Judaism. The voting bar is high - a 75 per cent majority is required to go ahead.

But whereas merger talks were unsuccessful some 80 and then 40 years ago, after two years’ painstaking preparation, it would be a shock if the scheme were to be scuttled at the last hurdle. As Baroness Neuberger, who has served as a rabbi at synagogues of both Progressive complexions, put it, the differences between them now are “vanishingly small”.

On issues of substance, on the question of who is a Jew, for example, their policies are closely aligned, whereas, previously, Reform adhered to recognition of only matrilineal status.

There might have been some cultural distinction, with Reform tending to present themselves as the loyal opposition to the Orthodox mainstream and the Liberals proud of their radical non-conformism, but this has become less conspicuous in recent years. And since rabbis regularly interchange pulpits between Liberal and Reform, the rationale for organisational separatism has diminished by the year.

As Rabbi Mark Goldsmith, who has also led both Reform and Liberal shuls, has observed, Reform has become more flexible in its interpretation of Judaism, while Liberal Judaism has become more appreciative of tradition.

If Progressive Judaism comes into being, it will be the largest Jewish denomination in the UK in terms of member synagogues, with some 80 congregations. But its 30,000 or so members, representing around a third of synagogue-belonging British Jews, will be fewer than the 36,000 of the United Synagogue.

Leaders believe that a single movement will be a stronger movement whose combined numbers will give it more clout on the communal stage and beyond. Meetings between Progressive leaders and ministers in the current government already signal greater intent to make policy-makers aware of its presence.

The unification process is paying practical dividends too in encouraging collaboration. The Reform and Liberal youth movements, while retaining their individual identity, are offering joint programmes for gap year and summer experience.

Most strikingly, a few weeks ago Radlett Reform and Elstree Liberal announced their intention to form a single Progressive community in Hertfordshire, beginning with joint activities. They believe the new synergy will raise the profile of Progressive Judaism in an area whose Jewish population is still growing. If the national union is approved, other synagogue partnerships may follow elsewhere.

But since the principle of pluralism is integral to Progressive Jewry, the new movement has pledged to respect internal diversity. Synagogues will keep their own customs and prayerbooks, for the time being at least. It is not clear whether their two Batei Din will merge.

Fundraising may become easier - one appeal dinner should be simpler to arrange than two. But more than that, leaders believe there are potential funders ready to back a united enterprise when they might not have donated to separate movements. Unification should also enable Reform and Liberals, who jointly spend around £4.7 million a year, to make administrative savings, freeing up resources to channel into areas such as student chaplaincy or outreach to young adults - which is currently dominated by Orthodoxy.

Leaders have declared their belief that Progressive Judaism is “the natural home for most of this country’s Jews” - a claim yet to be borne out in practice. But they hope that a united movement will better equip them to reach an estimated 75,000 Jewish households currently unaffiliated to a synagogue.

Rabbi Michael Shire, the former vice-principal of London’s Leo Baeck College, said the move “opens doors to a wider constituency with greater outreach”.

The rising rate of intermarriage in the UK - up from 24 per cent in the first decade of the century to 34 per cent according to the latest Institute for Jewish Policy Research poll and double the 17 per cent of the 1990s - will be a test. If Progressive Judaism can attract an increasing proportion of mixed-faith couples to bring their children up as Jewish, that will be one yardstick of success.