The number of people in public sector schemes has risen slightly over the same period, from 4.2m in 1991 to 5.3m in 2011.
When comparing the number of people holding defined benefit and defined contribution workplace pensions, the ONS’s companion research, the annual survey of hours and earnings, revealed that the total number of DB pensions holders fell from 10.49m in 1997, to 7.3m in 2012.
However, the number of DC pensions holders fell from 2.02m in 1997 to 1.82m in 2012.
Meanwhile, the number of workers with no pension provision increased from 10.39m in 1997, to 13.96m in 2012.
Rob Simpson, managing director of Warwickshire-based Simpson Financial Services, said: “Numbers are a concern, but there is also a wider choice when retirement planning, such as investment properties and Isas. As an adviser, it is often easier to discuss these options rather than charge a 21-year old £600 to put their money in a pension scheme.”