The total Christian population is 13.2 million, or 61 per cent, down three percentage points. Catholics have dropped half a percentage point to 25.3, or 5.4 million, Anglicans are down 1.6 percentage points to 3.7 million, while the Uniting Church is down to 5 per cent, or 1.1 million people.

Minority religions all showed strong growth, particularly Hindus, whose numbers nearly doubled to 276,000, from 0.7 per cent to 1.3 per cent. Buddhists have risen from 2.1 per cent to 2.5 per cent, Muslims from 1.7 per cent to 2.2 per cent.

Professor Bouma said Hindu growth was due to migration, and the recent Muslim growth was due to continued migration from south Asia and a high birth rate.

''The rise in no religion continues its historic trend, even in the face of an apparent small rise in claiming a religious identity. So polarisation is increasing,'' Professor Bouma said.

In five of eight states and territories, ''no religion'' provides the largest group. In Victoria and Queensland it is second, behind Catholics, and in New South Wales it is third, also behind Anglicans.