The Church of England is on its "last chance" and must make some hard decisions about clergy and parishes if it is to have a future, according to a leading academic.

Linda Woodhead, professor in sociology of religion at Lancaster University, said: "What my and other people's research shows is that people of my age are the last generation who in large numbers care about the Church of England."

Prof Woodhead, aged 50, told Christian Today: "I am of the very last generation that has any interest in investing in the Church and to think about its future." She doubted that the Church would die out completely, but warned it was in danger of shrinking into small enclaves dominated by the white middle classes.

Some of her concerns will emerge in more detail, along with groundbreaking new research, in an Enquiry on the Future of the Church of England launched this week in Oxford. The series of five debates, beginning tomorrow night, Thursday, will examine parishes, people, heritage, diversity and vision.

She said the Church is still one of Britain's great cultural institutions, but recent research shows that it is at a crisis point. In the UK as a whole, just one in ten of those aged under 20 now identify as "CofE", compared with a majority of over-70s. More younger people now identify as having "no religion".

She said the parish system, where every square foot of England falls into a delineated parochial area, and the tradition of the Church paying for clergy accommodation would all have to be reexamined if there was to be a sustainable future.

Contributors at the five debates will include the social entrepreneur Lord Mawson on the future of the parish system, Dame Fiona Reynolds of the National Trust on the future of church buildings, Sir Tony Baldry MP, Second Church Estates Commissioner, on how the church can re-engage people, Canon David Porter of Lambeth Palace on dealing with splits within the church and Professor Diarmaid MacCulloch, the historian, on what the Church can offer the next generation.

A new YouGov survey of 1,500 Anglican clergy, to be published later this month, is expected to add to concerns about the Church's present direction.

The opening debate on Thursday 9 October will challenge whether the present parish system, designed for a rural society, is appropriate for an urban, mobile population.

Prof Woodhead added: "The Church of England is one of five great British cultural institutions, but it is in crisis. If it is to survive it needs an urgent injection of fresh thinking and radical reform. These debates are designed to offer just that. They grow out of research which shows how rapid the Church's decline now is. In living memory it has gone from being the church of the majority to that of a shrinking minority. The debates ask whether the CofE has a future as a national church, and if so in what form."

The debates will be at the University Church of St Mary the Virgin, Oxford.