THIS WEEK church pews will be filled with those who turn up only for high days, holidays, hatches, matches and despatches.

But this group of uncommitted believers who are attached to no particular church but who have a real and genuine interest in spiritual matters have been classified into a new denomination called "Fuzzy Fidelity" by researchers.

The headache for the established churches is that this group now makes up more than half the European population.

Now some congregations are fighting back, holding services in shops and gyms in an effort to attract uncommitted believers into the church.

This new denomination has only a vaguely defined notion of a "divine entity" and says religion makes little difference to their lives, according to Professor David Voas of the Cathie Marsh Centre for Census and Survey Research in Manchester, who used the massive European Social Survey to pinpoint the emergence of the group.

"The fuzzy faithful have become so numerous because people are ceasing to be actively religious much more quickly than they are becoming wholly secular," said Voas.

"The sheer size of this group means that upon their attitudes and behaviour will hang the future role of religion in Britain.

"Many continue to pray, but have relinquished specific Christian beliefs, such as Jesus being the son of God. They go to church only for the main festivals or for life's rites of passage."

Voas has divided this group into subgroups "Spiritual Seekers" and "Sheilaists". Spiritual Seekers have beliefs about the afterlife and fate that have nothing to do with organised religion.

The term Sheilaists derives from an interview with a woman called Sheila who defined her religious conviction as: "Sheilaism: I just have a little voice in my head."

The 2001 Census revealed 67% of the UK's population said they had a religious belief, but only 11% said they were regular churchgoers.

"There are those who are trying something alternative to traditional church gatherings and I know of congregations coming together in Starbucks or the gym or wherever it may be," said Rev Angus Morrison, convener of the Church of Scotland's Mission and Discipleship committee.

"We have to be proactive and holistic in our approach. The hope is to find ways of co-operation in a way that will benefit the old and the new. The focus is on reaching those people in the places where they congregate.

"It is the reality of the modern world that more people go to the shopping mall than the church these days. At this time of year we see so many people come to church who normally do not, but we always see this as an opportunity to reach out and have contact with them.

Morrison said church attendances had been declining steadily over more than 200 years, leading to a situation where Western populations had become "de facto materialists".

"It is an enormous challenge for the churches to draw in those with a generalised spirituality. These are people who have a longing for meaning and I think it presents the church with something of an opportunity."

While the Kirk is looking into ways of communicating with the uncommitted, the Roman Catholic church in Scotland said it had no plans to move out of traditional churches.

Peter Kearney, spokesman for Scotland's Catholic bishops, said: "I don't think we should be setting up churches in shopping centres, which is where most people go these Sundays. We should be consistent, timeless and sturdy and hope we are still here when they come looking for us.

"What we can do about it is pray for them, rather than go chasing them. We need to let them know we are here all year round and that we are ready for them to return to the church.

"I do think this research gives us hope. The key point is that this shows that only a small proportion of the population has no religious belief whatsoever. In that sense it is surprising and quite heartening to see."

But Voas fears it may already be too late for organised religions. "Fuzzy fidelity is not a new kind of religion or a proxy for as yet unfocused spiritual seeking," he said.

"It is a staging post on the road from religious to secular hegemony."