The information requested falls within the responsibility of the UK Statistics Authority. I have asked the authority to reply.Letter from Karen Dunnell, dated January 2009:"As National Statistician, I have been asked to reply to your Parliamentary Question how many and what percentage of children lived in workless households in each year since 1997, broken down by parliamentary constituency. (249370)""The available information is provided in the table. A copy of the table has been placed in the Library of the House.""The information requested has been answered using annual estimates derived from the Annual Population Survey (APS) household dataset, which are only available from 2004. Estimates before 2004 are derived from the Labour Force Survey and are of insufficient quality for answering this question due to the detail requested. It is vital to note that as with any sample survey, estimates from the APS are subject to a margin of uncertainty as different samples give different results.""Figures are based on children in working age households. A working-age household is a household that includes at least one person of working-age, that is a woman aged 16 to 59 or a man aged 16 to 64.""Estimates that are deemed unreliable for practical purposes are presented in italics. These estimates arc based on small sample sizes and are subject to large variability. Estimates that are reliable are shaded."