The Movement for Reform Judaism, Liberal Judaism and the Masorti movement are decentralised structures. Each synagogue building is owned directly by its membership and the rabbis employed by the congregation. As a result, non-Orthodox rabbis must have a strong entrepreneurial streak to add to their spiritual leadership in order to survive.

Rabbi Mark Winer of the Reform’s West London synagogue has turned his building into a 24/7 business offering facilities for prayer, study, meetings and a full-time crèche. “Our budget when I came in nine and a half years ago was £1.6 million. Now it is £3.3 million.”

Rabbi Winer has supplemented his degrees and doctorates from Harvard and Yale with a couple of years at Harvard Business school. He calls his London congregants “equal share stockholders” and entices wealthier members to give generously.

Three years ago Rabbi Winer installed a chief executive, Alan Shapiro, and four deputy executives, each given the task of raising money for services identified as key but underfunded. A new patrons programme helps to direct donations from the wealthy into causes ranging from education to retaining members who marry non-Jews. “A synagogue is what I call a condominium of dreams. We give people the opportunity to fulfil their dreams. There are people who love to give away their money,” Rabbi Winer said.

West London members Raymond and Arnold Burton – sons of the late tailoring mogul Sir Montague Burton who arrived penniless from Russia – have donated over £1 million to build a new affiliated synagogue in St Petersburg. Another member is paying more than £650,000 to restore the synagogue’s organ.

The Movement for Reform Judaism has 43 other synagogues in its association, while Liberal Judaism has 33 autonomous communities comprising 10,000 members, Rabbi Danny Rich, its chief executive, said.

In the two years since Rabbi Rich took over the running of Liberal Judaism, he has increased the budget from £900,000 to £1.2 million.

Rabbi Rich has also established a system of wealthy “patrons” into Liberal Judaism who fund and entice others into “a new creative experimental fund” to pay for educational programmes. Founding patrons include Sir Evelyn de Rothschild of the banking dynasty, Stanley Fink, the deputy chairman of Man Group, Ronald Thwaites QC and Lord Haskel of Higher Broughton.