My two young sons attend a Church of England primary school and so receive very little in the way of religious instruction. God is allowed into the school, every now and then, under supervision, but He is not allowed to meddle too much in the classrooms and He is barred from attempting to persuade the children to adopt an outlandish dress code in praise of His munificence, benevolence, etc.

But then, that’s our established church for you. It’s not very dogmatic, is it, Anglicanism? Indeed, the Church of England seems at times a little suspicious of God. Anglicanism is a bit of a lily-livered creed which would be heartily despised by Shabina Begum, the 16-year-old girl who persuaded the Appeal Court that she had every right to wear a jilbab — a top-to-toe expanse of hessian sacking with a small aperture for part of the face — to her “multi-faith” school in Luton.

Shabina is a Muslim and the Koran certainly insists that women should dress modestly, so as not cruelly to torment the inflammable, uncontrollable loins of men. There is some debate within the world of Islam about the degree of modesty demanded by Allah. But Shabina subscribes to an interpretation that insists that Allah wants the whole lot covered up in sacking.

There is little doubt that, were Shabina not a Muslim but nevertheless demanded the right to wear such clothing and, further, cited a wish to protect her feminine modesty from the eyes of lascivious men as the reason for so doing, she would be swiftly referred to a psychiatrist for counselling. But she is a Muslim, so she wasn’t. Instead, she — and her supporters — have got their way.

Her supporters, incidentally, are Hizb ut-Tahrir, an organisation founded in 1985 by the giggling, publicity-crazed “Sheikh” Omar Bakri Mohammed, whose recent claim to fame has been to encourage young British Muslims to join Al-Qaeda and who has condoned suicide terrorist attacks.

How delighted he must be that his protégés have been able to utilise a piece of international law to win a famous victory against the loathsome kufr, or infidels. He will be giggling into his beard even more than usual.

Except that the real targets of Shabina’s legal action were not really the infidels, or the government, but Denbigh high school in Luton and, more especially, the British Muslims who send their children to it; those lax and lamentably unrigorous British Muslims; those British Muslims content to dispatch their daughters to school only 90% covered up, rather than 99% covered up.

To tell you the truth, on this narrow issue I’m with Shabina and “Sheikh” Omar Bakri; for the real problem is Denbigh high school, not Shabina Begum and that thing the government calls “radical” Islam, horrible though Hizb ut-Tahrir most certainly are.

The school is made up of 79% Muslim students and has been praised pretty much everywhere for its cultural tolerance and ability to accommodate diversity. In other words, it is a school which has embraced the concept of multiculturalism.

There is a school uniform, of sorts, but as a dispensation Muslims parents have been allowed to sheath their daughters in clothing that envelops 90% of the body. Not 99%, mind you — that’s going a little bit too far. Just 90%. And the school has sorted all of this out with local mosques and “community leaders”.

This is why we should be worried about Denbigh high school and multiculturalism generally. It is one thing for a rancid, stone-age clique like Hizb ut-Tahrir to insist upon the metaphoric subjugation of women by dressing young girls from top to toe in sackcloth and ashes. It is another thing entirely for a sort of Allah-lite version to have been institutionalised in state schools and for the rest of us to smile indulgently and pretend that it is evidence of “tolerance” and “ diversity”.

It is tolerance of a kind, I suppose: tolerance of the intolerant strictures of an extremely conservative but potent religion.

For 40 years or so British women have wrestled to change an education system which for a long time seemed to disfavour them academically. At the same time they have attempted to eradicate from the national psyche the notion that errant or peripatetic male lust is the fault and responsibility of women. Those battles once seemed to have been won; but at Denbigh high school — and countless schools like it — they are right back where they started.

Just recently the politicians have wised up and begun to disown multiculturalism. Even the boss of the Commission for Racial Equality, Trevor Phillips, has described the concept as no longer relevant. In the wake of 9/11 it is feared that British Muslim communities, which are becoming ever more conservative, will fatally undermine the sense of national cohesion, the fragile and tenuous glue that holds us all together.

What we need now is to inculcate a “core of Britishness”, to quote Phillips. But a state school which kowtows to the un-British (for want of a better phrase) demands of its black and ethnic minority constituency is far more damaging to this national cohesion business than an insignificant little ginger group such as Hizb ut-Tahrir.

We cannot force parents to inculcate that core of Britishness in their homes; but we can ensure that it takes place in our schools. The French seem to have grasped this point; it is about time that we did. Instead, we rail about Hizb ut-Tahrir — and Omar Bakri and Abu Hamza, cartoon bogeymen who don’t actually matter a damn. It is what mainstream Muslims do that matters in the long run.

It is interesting that on this occasion our national cohesion has been attacked from within and from without. It was the Appeal Court judges’ interpretation of the European Convention on Human Rights that led them to decide that Shabina Begum could wear whatever she liked to school.

Of course, it is very difficult to inculcate a “core of Britishness” and maintain national cohesion if the nation state is judicially subordinate to a powerful international body of law, some of which we have voted for and some of which has been imposed upon us by the EU. In other words, the weaker the nation state, the weaker the sense of national cohesion.

The previously amenable Dutch are finding this out: hand-in-hand with a rather vicious backlash against the demands and complaints of Dutch Muslims has been a sudden and surprising disaffection with Brussels. It has been portrayed as a swing to the right, but I am not sure that there is anything particularly right-wing about trying to preserve the benefits of a very liberal culture.

The Dutch are merely asking themselves: what is Holland actually for? What is its point? Does it stand for anything or is it just an ad hoc amalgam of disparate groups ruled from 200 miles down the road in Belgium? I suspect that, thanks to Shabina, we will soon be asking the same sorts of question over here.