London, England - Roman Catholics have overtaken Anglicans as the country's dominant religious group. More people attend Mass every Sunday than worship with the Church of England, figures seen by The Sunday Telegraph show.
This means that the established Church has lost its place as the nation's most popular Christian denomination after more than four centuries of unrivalled influence following the Reformation.
Last night, leading figures gave warning that the Church of England could become a minority faith and that the findings should act as a wake-up call.
The statistics show that attendance at Anglican Sunday services has dropped by 20 per cent since 2000. A survey of 37,000 churches, to be published in the new year, shows the number of people going to Sunday Mass in England last year averaged 861,000, compared with 852,000 Anglicans worshipping.
The rise of Catholicism has been bolstered by an influx of immigrants from eastern Europe and Africa, who have packed the pews of Catholic parishes that had previously been dwindling.
It is part of the changing face of churchgoing across Britain in the 21st century which has also seen a boom in the growth of Pentecostal churches, which have surpassed the Methodist Church as the country's third largest Christian denomination.
Worshipping habits have changed dramatically with a significant rise in attendance at mid-week services and at special occasions - the Church of England expects three million people to go to a parish church over Christmas Eve and Christmas Day.
In an attempt to combat the declining interest in traditional religion, the Anglican Church has launched radical new forms of evangelism that include nightclub chaplains, a floating church on a barge and internet congregations.
The Rev Alister McGrath, professor of historical theology at Oxford University, said that the church attendance findings from the organisation Christian Research should act as a wake-up call to the Church of England.
"While it can rightly point to the weight of history, the importance of cultural memory, the largest number of church buildings and nominal church members in defence of its continued status as the established church, there is clearly a problem emerging," said Prof McGrath, one of Anglicanism's most respected figures.
"What happens if the established church becomes a minority church?"
The Catholic Church has also suffered a serious fall in the size of its congregations, but the expansion of the European Union in 2004 resulted in its numbers being bolstered by the arrival of hundreds of thousands of Poles and Lithuanians.
Attendance at Mass in 1991 was recorded as 1.3 million, a drop of 40 per cent since 1963. But over the past six years it has fallen by only 13 per cent, with the rate of decline slowed by immigrants from Catholic countries.
The Rt Rev Crispian Hollis, the Bishop of Portsmouth, said that the Roman Church had been active in trying to win back lapsed worshippers, but conceded that mass immigration had been a significant factor in swelling its numbers.
"The number of Catholics attending church has been catching the Anglicans over a number of years," he said.
"We don't want to be seen to be scoring points over the Anglican Church as we are in no way jealous of its position as the national church, but of course these figures are encouraging. It shows that the Church is no longer seen as on the fringes of society, but in fact is now at the heart of British life."
Danny Sriskandarajah, the head of migration, equalities and citizenship for the Institute for Public Policy Research, said that its research indicated that pews would not stay packed for long.
"We are already seeing numbers from eastern Europe dropping and many of them have already returned home," he said. "It is an important phenomenon, but it is likely to be temporary. I doubt we'll be seeing this level of attendance in another 10 years."
Churchgoing in Anglican and Catholic parishes had stood at about a million each for the past 10 years, though the relative equality in their numbers over recent years is surprising considering that there are 25 million people who regard themselves as Anglicans, and only 4.2 million Catholics.
"It isn't a competition. I'm delighted to see all Christian denominations flourishing," said the Rt Rev Graham Cray, the chairman of the Church of England's report on evangelism.
"Large numbers of eastern Europeans have come in to the country, which has certainly strengthened them as has happened with non-whites in central London churches."