Dissident Jewish groups that refuse to toe the communal line on Israel - solidarity at all costs - were once few and far between. Nevertheless, in the 1960s and 1970s the Marxist group Matzpen, and in the 1980s the Jewish Socialists' Group, small and isolated as they were, irked the Jewish establishment to a surprising degree.
Today, there are many more groups opposing Israeli policies and criticising or rejecting Zionism. They include Jews for Justice for Palestinians, Peace Now UK, Independent Jewish Voices, Jewdas and at least five or six others. Although the Jewish establishment and right-wing pro-Zionist groups would prefer it if most of these groups ceased to exist, the increasing number of Britain's Jewish population of 300-330,000, not known for departing from the communal consensus, who have gravitated towards them is a sign of a significant change. Just how effective they are, however, is now being severely tested following Israel's decision to launch a war on Gaza on 27 December 2008.
There is no doubt that despite policy differences between these dissident organisations on the nature of any final peace arrangements between Israel and Palestine, their opposition to Israel's Gaza war has been unanimous. Those groups with active websites have issued strong statements. Letters have been sent to the press and to politicians and public figures. Members went onthe anti-war demonstrations in January in London.
Despite what appears to be a mounting level of action, it also seems clear that there is a deep sense of frustration as to how to mould these various initiatives into an effective response rather than just a cry of anger and pain. While the expression of such emotions is important, since one of the purposes of these groups is to be an outlet for the reactions and feelings of Jews who simply want to speak out on these issues as Jews, achieving the goal of influencing opinion, provoking a reaction from community leaders, politicians and Israeli officials, and demonstrating to the wider world that Israel's actions run counter to progressive Jewish values are also a high priority. Three factors are hampering success.
Polarisation of opinion
Growing support for a critical stance towards Israel was partly a reflection of the severe polarisation of opinion among Jews, which has been developing since the turn of the century. The collapse of the Oslo accords, 9/11 and the beginning of the Bush-Blair war on terror, the increased anti-Jewish hostility some commentators link to intensified extreme criticism of Israel, and the coming to power of the Sharon government led some Jews to a more definitive and open opposition. But it led others, especially a hitherto rather muted conservative Jewish leadership, to move in the opposite direction.
This loyalist backlash, although rather inchoate at first, eventually resulted in the creation of a much more defensive, fearful, ethnocentric atmosphere in the organised Jewish community. It was based on alarm at the so-called 'new anti-semitism' (defined as vilification of Israel), characterised Muslims as a threat to Jews and rallied around an Israel whose existence was perceived as under threat from, among other things, suicide bombings, rockets fired from Gaza and the power of Hizbollah in Lebanon.
Those behind this increasingly organised and determined effort, who had excellent relations with the Blair government and the support of some high profile columnists, succeeded in creating an impression that most Jews have no truck with the critical stance of the dissidents. So, even as critical groups were gaining more adherents, barriers to having a greater impact on the organised community were raised.
Lack of coordination
Producing a response that reflects the potential of the enlarged critical sector has also been handicapped by the lack of coordination among the groups. This is partly because of the organic way they have developed - often triggered by violent crises - and the nature of some of the people involved, who tend to be rather independent minded and reluctant to make long-term organisational commitments. But it's also partly because of political differences.
Some groups support pressurising Israel to change course through various forms of boycott. Others oppose such measures. Some take a critical Zionist stance and fully accept Israel's legitimacy. Others are ready to countenance a questioning of that legitimacy and see a one-state solution as reasonable. Some are ready to use the word 'apartheid' to describe Israel's policies in the occupied territories. Others find such language unacceptable.
The fact is that views on these issues are strongly held and make practical cooperation on policy difficult. Many in the dissident groups are aware of this problem and have been trying to find ways of producing common platforms based on principles or of reaching common, minimal positions. But if the common denominator is too low, while the strength of feeling about Israel's actions is very high, everyone is left dissatisfied.
The media war
The third factor limiting an effective response to the Gaza war is the unprecedented, tightly coordinated, relentless public relations campaign being waged by Israeli spokespeople. This is being backed up in the UK by BICOM, the Britain Israel Communications and Research Centre, a well-funded media-focused organisation.
In the past Israel has often put out confused messages about its intentions, delivered by people with poor media skills who were liable to be derailed at the first incident of major civilian casualties, especially where children were involved. The current effort has been rigorously planned over the past few years and the Israeli message heavily dominates the media. In these circumstances, with alternative voices - whether Palestinians caught up in the conflict, representatives of the PLO or Hamas, local Muslim writers, academics - fighting for space, it's not surprising that dissenting Jews find it difficult to get attention.
At the time of writing, the war continues. Depending on the direction it takes, further opportunities may arise for critical Jewish groups to make their voices heard. If doubts are sown in the wider Jewish community as a result of more incidents like the killing of people seeking shelter in a UN school, or mounting Israeli military casualties, there may be greater readiness to listen to the arguments of dissenting Jewish groups, if they are couched in language that does not alienate those very many Jews who are reluctant to listen to the truth.
Given that the pro-Israel consensus among the organised Jewish community in the UK was so robust from the 1960s through the early 1980s, the current, far more fragmented picture represents a remarkable change. The organised dissident groups are only one part of the story. Although it is not easily quantifiable, there is growing anecdotal evidence that many Jews are deeply uncomfortable with the way Israel treats the Palestinians, but do not feel that they can find the space or the language for exploring their concerns. It's one of the challenges facing Jewish groups critical of Israel: to find a way of giving such Jews a voice. The war on Gaza may well be another bloody milestone on the path to this aim.
Antony Lerman is the former director of the Institute for Jewish Policy Research in London.