It was miserable timing. Two weeks ago, the JC revealed that a number of activists in the UK were trying to establish a left-leaning Israel group, which would support Israel but not shy away from criticising its government. The initiative, which is being spearheaded by Hannah Weisfeld, formerly of the Jewish Community Centre for London, was directly inspired by the liberal American lobby group, J Street, which, since it was founded in 2008, has increasingly challenged the more conservative Jewish establishment.
And then, last week, J Street crumbled. The Washington Times revealed that a large chunk of its funding - $750,000 since 2008 - came from the family of Jewish financier George Soros, known for his anti-Israel views. At the height of the second intifada, he blamed the rise in antisemitism on the Israeli government; he also declared that he does not "deny the Jews their right to a national existence - but I don't want to be part of it".
J Street had consistently denied that they had received his money but it seems that they had blatantly lied. Many of J Street's supporters were furious; the group, which had promised "ethical" criticism of Israel, had no ethical credibility itself.
An additional revelation, that J Street had facilitated meetings between Washington officials and Judge Richard Goldstone, lead author of the damning UN report on Operation Cast Lead, seemed to doom J Street's brand.
A couple of weeks ago, our own local doveish activists were hoping that some of J Street's magic would rub off on them. Now, they must learn the lessons of its downfall.
J Street was established to counter AIPAC, the right-leaning, dominant Israel lobby. From the beginning, J Street's loyalty to Israel was questioned by elements on the right. It billed itself as "pro-Israel, pro-peace", in an attempt to reclaim the "pro-Israel" label, which had been increasingly monopolised by right-of-centre Jewish leaders and Christian Evangelicals.
J Street took some controversial positions, for example supporting dialogue with Hamas and calling for an immediate ceasefire on the first day of Operation Cast Lead. However, it was clearly nervous that these positions were unpalatable to mainstream American Jewry. Its website hosts a long section devoted to debunking myths about itself, in which it seeks to justify - or, rather, obfuscate - its policy choices. It only sought "indirect engagement" with Hamas; it questioned Israel's Cast Lead "strategy".
As the pressure mounted - with Israeli Ambassador to Washington Michael Oren refusing to attend its inaugural event - J Street seemed uncomfortable in its own skin. It was arguably not the association with Soros that provoked so much anger among its supporters, but its fudging of the truth. Its donors and hardcore supporters wanted one thing, its fellow-travellers and the wider community wanted another; J Street never managed the balance.
I have no doubt that the organisers of the UK version of J Street are genuine friends of Israel. But they must know that any liberal Israel group here will be subject to the same accusations of disloyalty. It is also inevitable that it will attract supporters who do not genuinely have Israel's interests at heart. This was certainly the case with J Call, a continental group that explicitly modelled itself on J Street last year.
The founders need to accept that they may not have full control over who backs them, and that not all these individuals will be Zionists. As a result, the group may evolve in unexpected and unwanted directions. If its founders are uncomfortable with this, they ought not to set up the group.
If they go ahead anyway, they must be absolutely honest and unapologetic about the group's political beliefs and funding sources. This risks its being pushed beyond the mainstream community's boundaries, but this is the real lesson of J Street. A liberal Israel lobby can please its more radical constituents, or stay relevant to the wider community - but not both.