Liberal Judaism chair Lucian Hudson has called for a closer alliance with the Reform movement, suggesting they combine forces in a joint federation.
Writing in the latest issue of the Liberal newsletter, LJ Today, Mr Hudson said he wanted to go beyond the old question of "merger" - the subject of failed talks between the movements.
Instead, they should "focus on what it would take to create a Progressive Federation of Liberal and Reform Communities, where each synagogue retains its distinctive identity, Liberal or Reform, yet is part of a joint endeavour reflecting common Liberal, Reform and Progressive values."
The Progressive community ought to "turn the centre of gravity away from speculation about the Chief Rabbi's successor and, instead, make visible and compelling the breadth and depth of British Judaism".
Mr Hudson said this week that reaction to his idea reflected "positive interest rather than suspicion. I know I am stirring things a bit but I am interested to see where it falls."
However, Reform chairman Stephen Moss said "discussions of that nature are not on the agenda" for the present.
At the Bet Tikvah Progressive Synagogue in Essex, Rabbi David Hulbert believed the concept of a federation was "very sensible and probably inevitable". He is particularly well-placed to comment as for many years he combined his role at Bet Tikvah with serving as rabbi for a local Reform synagogue, Sukkat Shalom.
He pointed out that rabbis for the two movements were both trained at Leo Baeck College and commonly switched jobs between the two.
Baroness Neuberger, who began in the Liberal movement, became senior rabbi of the Reform's flagship West London congregation last year. Rabbi Mark Goldsmith, now chairman of the Assembly of Reform Rabbis UK, was previously at Finchley Progressive. Rabbi Alexandra Wright moved from Radlett and Bushey Reform to be senior rabbi of the Liberal Jewish Synagogue, St John's Wood. Former Liberal head rabbi Charles Middleburgh is minister of Cardiff Reform.
The view of Maidenhead Reform's Rabbi Jonathan Romain is that "if federation is an alternative model to merger, then it has definite possibilities because there is so much the two movements have in common - but we still have to respect differences. But if it is a cover word for merger, it simply won't happen."
Hendon Reform's Rabbi Steven Katz felt there were too many differences to surmount. For example, the Liberal movement accepted the child of a Jewish father and non-Jewish mother as Jewish - if raised as Jewish - and allowed rabbis to give blessings at mixed-faith unions.
He feared an umbrella body could turn out to be a "step too far, leading to fractiousness and constant bickering.
"It is sometimes difficult enough to achieve overarching unity, even within the Movement of Reform Judaism, without expanding it to include another 20 congregations."