According to statistics published this week in the annual British Social Attitudes survey, 9 per cent of those questioned last year said they were Catholic, compared to 10 per cent of those asked in 1983.
This compares with a decline from 40 per cent to 20 per cent of those saying they were Anglican during the same period.
The stable proportion of Catholics is believed to have been maintained initially, in part, by a higher than average birth rate, and latterly by large-scale immigration from countries with large Catholic populations.
The proportion of Christians identifying with other Christian denominations also remained stable at 17 per cent.