I think I should start by declaring an interest. I am a member of the Executive Committee of Jews for Justice for Palestinians, which seems to be one of the groups that Jacobson is targeting in "The Finkler Question". I think the novel is well-written and at times entertaining. But I agree with an earlier reviewer (TomCat) that the sections about the "ASHamed Jews" (which are actually a major part of the book, though many reviewers don't mention them) are crude political propaganda - which is surely very detrimental to a work of fiction - rather than satire. Of course I am biased against the novel, but it is such blatant political propaganda that it calls for a political response.
First: all these groups, including anti-Zionist groups such as JAZ (Jews Against Zionism) (JfJfP is not an anti-Zionist group) reject entirely the label imposed on us by Jacobson that we feel "ashamed" of being Jewish - on the contrary, we are asserting a universalist and prophetic Jewish identity of which we are proud and which this book repudiates. Instead, Jacobson retreats into tribal paranoia. The extreme paranoia about antisemitism in Britain, and the exploitation of the accusation of antisemitism in order to deflect criticism of Israel, are themselves worthy of satire.
I think true satire should contain some compassion and understanding for the characters, rather than the over-the-top fantasising in which Jacobson indulges. For instance, there's a founder-member of the ASHamed Jews who is obsessed with the fact that he is circumcised and spends his whole life sitting naked on a chair pulling at what remains of his foreskin in an attempt to lengthen it - he does this all morning and then spends the rest of the day posting written accounts and photos of his efforts on his blog. And the caricatures of real people result in one-dimensional, cardboard characters.
The book can be very inconsistent and illogical. At one point two non-Jewish characters are discussing the "ASHamed Jews" in a very puzzled way, asking why Jews living in Britain should be ashamed of Israel's actions, which have nothing to do with them - then later on, at an "ASHamed Jews" meeting, Finkler objects to the idea of a boycott of Israel, saying Israel is their "family" - "Whoever boycotted his own family?". So here it is clear that Jews ARE very much associated with Israel.
Against the background of Operation Cast Lead, the author writes of Finkler (with evident approval) "Gaza didn't do it for him" and (again with authorial approval; indeed Finkler stops being a character and becomes a mouthpiece for Jacobson's political views) Finkler doesn't understand why Israel's response is called "disproportionate". (According to the Israeli human rights group B'Tselem, in Gaza 762 civilians and 330 combatants were killed - these figures exclude 248 police officers; 13 Israelis were killed, including four civilians.) I've recently been reading "The Punishment of Gaza", by the Israeli journalist Gideon Levy - a book containing articles expressing his anguish over the atrocities committed during Cast Lead; and to read Jacobson after that is truly appalling. I suggest that everyone who has lauded this novel reads Gideon Levy's book. As I've said above, if a novelist decides to spoil his novel by including large chunks of political propaganda, then he issues an open invitation for his work to be judged in political terms.