ON FRIDAYS about 6,000 men and women gather for prayers at the East London Mosque in Whitechapel. They are a diverse bunch: Algerian, Bangladeshi, Indian, Moroccan, Pakistani, Somali, South African. The mosque’s imams preach every sermon three times, in different languages. They are now looking for a new imam to join them. Among the requirements are that he be British-born and speak English.

The Muslims who came to Britain in the 1960s and 1970s, mostly from Bangladesh and Pakistan, brought their religious leaders with them. Few spoke English, nor did the government require them to do so. Stranded in the smokestack towns of northern England, struggling to decode the broad local accents, Muslims found comfort in hearing their mother tongues at the local mosque.

That is now changing. Nobody knows exactly how many imams there are in Britain, let alone what languages they speak. But Muslim leaders such as Ibrahim Mogra, a Leicester imam and senior member of the Muslim Council of Britain, say that the number of English-speakers is growing. And fewer preachers are coming from abroad, he reckons.

Official pressure is one reason. In 2006, the year after Islamist suicide-bombers killed 52 other people in London, the Mosques and Imams National Advisory Board was established to develop standards on issues such as the accreditation of imams. A government review published in 2010 concluded that imams were not equipped to help young British Muslims cope with problems such as unemployment, racism and drugs. It suggested better accreditation and more thorough training in subjects beyond theology. The visa regime has gradually tightened and English language requirements have been introduced for those who wish to enter Britain specifically as religious ministers.

Another reason is simple demography. The children and grandchildren of those who came to Britain half a century ago may understand Bengali or Urdu, but English is their mother tongue. They want leaders who speak it. Mr Mogra’s children will only come and hear him preach if he does so in English, he says.

Islamic seminaries teaching Koran recitation and theology have operated since the 1970s. But in recent years a small but growing number of academies have started offering more than dogma. At the Cambridge Muslim College, for example, mosque administration, counselling and dealing with the media, along with modern British political history, are all part of the curriculum.

Still, not all trainees go on to become imams. Part of the problem is money. A big mosque like the one in Whitechapel is able to pay its imams a decent wage because it rents out its building. Smaller ones, which rely on donations from their congregations, struggle. Like many immigrants, foreign-born imams are often willing to work for less. And older congregants may respect foreign imams more, says Tim Winter, a convert to Islam and dean of the Cambridge Muslim College: they are seen as more learned.

The rise in locally born and trained imams is part of British Islam’s transition from an immigrant religion to a home-grown one. But more important than the language that imams use are the attitudes they espouse, says Mr Mogra. Fluency in English is no guarantee of moderation. Omar Bakri and Abu Hamza, extremist clerics banned from Britain for inciting violence, speak it fluently.