Mr. John M. Taylor
To ask the Chancellor of the Exchequer if he will list those 1901–1991 decennial population censuses(a) for which the then Registrar General did not promise informants that the householders' forms would be treated as confidential for 100 years and (b) for which the Lord Chancellor has not granted, and is not intending to grant, the Registrar General statutory permission for an extended 100-year retention of the census forms. 
§ Ms Hewitt
In the period 1901–1991, only the 1981 and 1991 Census forms have contained specific assurances from the Registrar General for England and Wales with regard to the 100 year closure period, as specified under the terms of the Lord Chancellor's Instrument 12 of the Public Records Act 1958.
Access to the census returns prior to 1920 is governed by the Public Records Act 1958, section 5(1). They are closed to public inspection for 100 years by virtue of Lord Chancellor's Instrument No 12 of June 1966. The returns for 1901 and 1911 are in the custody of the Public Record Office.
Access to the census returns of 1921, 1951 and 1961 is covered by the Census Act 1920, as amended by the Census (Confidentiality) Act 1991. The Public Records Act 1958 section 3(4) permits those public records selected for permanent preservation to be retained for more than 30 years by the person responsible for them, with the Lord Chancellor's approval. In the case of census returns that person is the Registrar General, and permission is sought from the Lord Chancellor for the retention of census records every 10 years. The Lord Chancellor has granted permission for the census records for 1921, 1951 and 1961 to be retained by the Registrar General. The census returns for 1931 were destroyed by fire, and no census was taken in 1941.
The census returns for 1971, 1981 and 1991 are similarly covered by the Census Act 1920, and the Census (Confidentiality) Act 1991. No retention instrument is yet necessary for the returns for 1971, 1981 and 1991 since the records are less than 30 years old.1205W