"By contrast, immigration from Africa and elsewhere has led to growth in Pentecostal churches, where the worship style is more flamboyant," Dr David Voas, a senior researcher at Manchester University's School of Social Sciences continued.
Pentecostals now outnumber Methodists at church services in England, according to a survey.
Evidence for the shift comes from the English Church Census, conducted by the independent charity Christian Research, and substantially sponsored by the Economic and Social Research Council.
The Church is in third place behind the Church of England and the Roman Catholic Church in terms of attendance.
The research will alarm leaders of the 200-year-old Methodist Church, which will next year celebrate the tercentenary of the birth of Charles Wesley, a prolific hymn writer, and the brother of John, the founders of Methodism.
According to the census, Sunday attendance at Methodist churches has fallen from 289,400 in 2005 to about 278,700 in 2006. The number of Pentecostals in church on an average Sunday has risen above 288,000.
"Black churchgoers in inner London, where they outnumber white attendees, are an important source of growth in the context of the national decline in church attendance," said Dr Voas. "So it is significant that 40 per cent of Pentecostals, but only four per cent of Methodists, are black."
The Methodist Church closed 264 churches between 1998 and 2005, more than any other denomination. During the same period, attendance declined by a quarter.
Meanwhile, Pentecostal numbers grew by a third, and new churches have opened.
Dr Voas said: "It seems inevitable that the Methodist Church will be reabsorbed into the Church of England. The Pentecostals have appeared out of nowhere in the last couple of decades, but it remains to be seen whether they can make significant inroads into the white population."
The Rev Jonathan Kerry, the coordinating Secretary for Worship and Learning for the Methodist Church in Great Britain, said: "It's always good news to hear of growth amongst Christians, regardless of denomination - we are not in competition."
He added: "Methodism was born out of revival movements in the 18th century. However, like many historic denominations, the Methodist Church now struggles to respond to new movements of God's Spirit without feeling that it is betraying the past."
The Church of England drew the biggest congregations for Christmas Eve and Christmas Day services last year - 2.8 million worshippers - since the Millennium, according to figures released yesterday.