The increasing influence of Islam on British culture is disclosed in research today that shows the number of Muslims worshipping at mosques in England and Wales will outstrip the numbers of Roman Catholics going to church in little more than a decade.

Projections to be published next month estimate that, if trends continue, the number of Catholic worshippers at Sunday Mass will fall to 679,000 by 2020.

By that time, statisticians predict, the number of Muslims praying in mosques on Fridays will have increased to 683,000.

The Christian Research figures also suggest that, over the same period, the number of Muslims at mosques will overtake Church of England members at Sunday services.

Church spokesmen point out, however, that a growing number of Anglicans worship at other times of the week.

The projections show that, if the Churches do not reverse their historical decline, there will be more active Muslims than Christians in Sunday services across Britain before the middle of the century.

The figures, based on Government and academic sources and the latest edition of Christian Research’s Religious Trends, come amid growing tensions over the place of Muslims in British society.

They follow fierce rows over the extent to which Islamic law should be recognised and over claims that “no-go” areas for non-Muslims are emerging in parts of the country.

Dr Rowan Williams, the Archbishop of Canterbury, provoked criticism by saying the introduction of some aspects of sharia into British society was “unavoidable”.

The Bishop of Rochester, the Rt Rev Michael Nazir-Ali, faced death threats after writing in The Sunday Telegraph that Islamic extremism was turning some communities into “no-go” areas “where adherence to this ideology has become a mark of acceptability”.

Peter Brierley, a former Government statistician who edited the latest Religious Trends, said that the continuing growth of the Muslim population since the 2001 census would have significant implications for society.