So I did some research on Mike Leigh actually

From an interview in The Guardian on the occasion of the move of Two Thousand Years from the Royal National to the West End (U.S. equivalent: Off-Broadway to On), which may be found href="http://arts.guardian.co.uk/features/story/0,,1755767,00.html:"> here.

'Leigh's parents met in 1936 at Habonim, the Jewish socialist Zionist youth group in Manchester. Both his mother's sisters made aliyah (emigrated to Israel), one in 1934, another in 1949. His parents had also considered making aliyah themselves but married at the beginning of the war and by the time it ended, his father had a doctor's practice in Salford. "There were always people in and out of our house who were off on aliyah," Leigh says. It was a kosher home, though they only went to synagogue now and again and they drove on the sabbath. "But it was very, very Jewish. My grandparents were immigrants - they talked in Yiddish - and there were some outreaches of the family where there were genuine frummers [Orthodox]." In 1960, like many Jewish teenagers, he went with Habonim to Israel for the summer, and hitchhiked there on his own the following year. Nevertheless, when he became a student at the Royal Academy of Dramatic Arts in London, he consciously escaped his Jewish identity because, as he writes in an introduction to the play, he was escaping being stereotyped; having so many other possibilities closed down. This seems to be a peculiarly British dilemma that does not afflict American Jews; in the US almost everyone comes from somewhere else. To be British is to have to suppress where you came from, to pretend you always came from here.'

Yes, pat on my back, I seem to have spotted the difference between an English Jewish family (with a kibbutznik Socialist background) and my American Jewish family (with its hoity-toity Norman Thomas Socialist background). In the play, when Josh demands of his grandfather, "What does being Jewish mean to you? Are you ashamed of it?" the old man grumbles, "You're born Jewish, and that's the end of it. Ashamed of it? Proud of it? You just are." He certainly doesn't believe it calls for any religious observance, and by the end of the play, Josh has accepted this family attitude as well: He was acting "Jewish" to attract God's love because his family was treating him as an embarrassment or refusing to notice him at all. Now that they do notice him, now that he feels loved again, and part of the conversation, he can forget about God.

Perhaps this is Leigh's sly – and devastating – sendup of religion, and what gets people involved in it. It certainly helps to explain my delight in polytheism and a multiplicity of deity, and personality – my cordial dislike of One Omnipotent Father before whom to cringe, desperate for notice and some sign, any sign, of affection. Better to interpret every thunderclap as that. At least the folks are talking to me.

'"There is no doubt whatever that there is a context in which there is a confusion between Jews and Israel," Leigh says. "That Israelis, for better or worse, bring it on themselves, is all I'll say. The play is a reflection, rather than a conclusive didact because that's what I do." In the play, the daughter, with her Israeli boyfriend, reflects how Zionism has changed from being "something positive and hopeful" to a dirty word. For the family, Zionism has been a disappointment because it has not lived up to its own founding values. To others, I point out to Leigh, it had only ever been a colonial movement bent on ethnic cleansing. "Given the events of even the 19th century, Zionism was inevitable," he replies. "Given the events of the 20th century, Israel was inevitable." The play is about disappointment, he says, twice during the interview. Political disappointment and, perhaps, disappointment at how one child, of whom you had high hopes, has turned out.'

A universal theme, seen, however, through a uniquely English-Jewish lens. (All great art reveals a particular lens on a universal question. "Man is the noblest study of all - says Man," as James Thurber put it. An American-Jewish lens would show a different play, a different way of exploring the questions; so would a French-Jewish lens, or a Russian-Jewish lens, or a South African-Jewish lens. And within the nationalities, the attitudes would certainly vary. I have friends who see everything through a self-consciously Jewish lens and (rather closer) friends who find their Jewishness irrelevant. This is a luxury they might not be allowed in other societies, but it is allowed in this one, and they revel in it, and American society permits them to. (Does it permit this to Muslims these days? But Muslim plays and novels have not been produced much in this society – yet. I'm looking forward to it. Can't read the Jews, mostly, but I love the Catholics.)

By the way, on Leigh's working methods, another Guardian article provides this:
"Leigh's idiosyncratic preparation for both his plays and films is well documented. The director shuns scripts in favour of improvisation and likes to spend time talking his actors through the people they are going to play.
It was reported that, with the exception of Imelda Staunton, who played the eponymous abortionist, the cast of Vera Drake was not told that the film was about abortion until their characters discovered for themselves what Vera did."