The shrinking [Christian] majority

"Britain is still a Christian country but the drift towards secularism continues. 

[...] 

The headline figures suggest that the United Kingdom remains a predominantly religious and mostly Christian country. Almost seven in ten (68.5 per cent) identify themselves to researchers as Christians -- far more than the 15 per cent who regularly attend church. Less than a quarter (23 per cent) profess no religion at all (although in Wales, the figure is considerable higher, at close to one in three. Of the population as a whole, 4.4% is Muslim -- more than all other minority faiths put together -- but still less than one person in 20. (The full IHS figures can be found here.) 
This picture of stability may be something an illusion, however. The last time this survey was conducted, in 2009-2010, the figure for Christian affiliation was 71.4 per cent and for no religion was just 20 per cent. A movement of 3 per cent from a Christian identity to a non-religious one in a single year is potentially a dramatic one. The annual population survey, which has included a religion question since 2004, records what looks like a consistent pattern. In 2004-2005, the figures stood at around 78 per cent Christians and less than 16 per cent having no belief. " 

New Statesman, Nelson Jones, 29 September 2011