The trouble begins when Jews stop being invisible

First it was attacks on ritual slaughter, then criticism of the practice of circumcision. Now comes a campaign against a Jewish eruv enclosure in north London. It all makes Matthew Kalman rather uneasy.

Later this month, BBC's Omnibus will broadcast a documentary on the Hampstead Garden Suburb in north London. This bold experiment in 1920s suburban living has become an exclusive, largely white, middle-class enclave whose tree-lined streets and smart, red-brick houses have become a magnet for comfort-seeking residents as diverse as Lulu, King Constantine, Lord Soper, Martin Bell, the Sultan of Brunei and Richard & Judy.

A large part of the programme is devoted to the controversy surrounding the eruv, a plan to erect a symbolic boundary around several square miles of north London, including parts of the Garden Suburb.

According to orthodox law, Jews are not permitted to push or carry most objects in public places on the Sabbath. This restriction does not apply to certain areas bounded by walls, fences or natural features such as rivers. If an eruv can be erected then orthodox Jews within its area will be able to take pushchairs and other non-essential items out on the Sabbath which will enable families to spend more of the day together.

Most of the proposed eruv will be delineated by railway lines, motorways and terraces of houses. In those places where such features do not form a continuous line, structures similar to telegraph poles will be erected to complete the boundary. Of 83 such poles, seven were planned for the Garden Suburb. The authorities concluded that the poles and wires would be all but invisible to non-users while of great benefit to many residents and granted planning permission.

However, approval came only after a bitter struggle in which some local residents waged a long campaign to have the scheme rejected. Although the Hampstead Garden Suburb forms only a small area of the eruv zone, it was within these leafy and exclusive streets that the battle has been most intense. Diehard opponents like Lord McGregor of Durris are threatening to take the decision to judicial review.

Supporters of the eruv cannot understand what all the fuss is about. They argue that the finished scheme will have as much practical effect on non-users as a parish boundary or postcode. Many non-observant Jews support it too. They may not observe or even understand such traditions but they respect the right of their orthodox friends to practise their ancient religion unhindered.

The debate has arisen at a time when the Anglo- Jewish community is experiencing rapid change. On its secular wing, Jews are quickly and happily assimilating into British culture and society. Jews are significantly more welcome in the clubs, boardrooms and golf courses of Britain than their (mostly) immigrant great-grandparents could ever have dreamed of. Meanwhile, on its religious wing, the Jewish community is becoming more observant. This, combined with greater Jewish knowledge, has fuelled the development of new religious facilities.

Kosher restaurants and Jewish schools are flourishing. The proposed eruv, an ancient Jewish facility first developed by King Solomon and now common in Australia, Israel and north America, was accompanied by an application to the same planning authority to build a new mikvah (ritual bathhouse).

But, while Britain may be more welcoming to Jews than ever before, it seems as if that welcome is warmest for those who leave their religion at the door. Even Lord Soper, the nonconformist champion who might have been expected to welcome this Jewish non-conformism denounced the eruv plan as an "impertinence".

The intensity of the opposition has raised serious questions about the limits of tolerance in a supposedly multi-cultural Britain. Jewish ritual slaughter is regularly the target of campaigns to have it banned. Over the past two years, attacks on the Jewish tradition of circum- cision have risen to an unprecedented level.

The pressure to shed religious observance and conform is intense. From the invitation to dine at a college high table to the need to impress the boss on a Saturday morning round of golf, Jews wishing to climb the professional and business ladder are faced with daily choices between their religion and their career.

Religious Jews have been alarmed to discover that their prospects can disappear overnight once their faith becomes too visible. Last year the Guardian newspaper encouraged the resignation of a young advertisement sales executive rather than let him have Friday afternoons off to observe the Sabbath. Perhaps they didn't realise that his brother, now an orthodox rabbi, had become famous for playing in the Varsity football match at Wembley in a kippa.

He, like the proposers of the eruv, saw no reason why Jewish religious practice should not be incorporated within the framework of a multi-cultural Britain. For the residents of the Hampstead Garden Suburb, that challenge remains.

`Faith & Reason' is edited by Paul Vallely