The information requested falls within the responsibility of the National Statistician, who has been asked to reply.
Letter from Karen Dunnell, dated 19 June 2007:
As National Statistician, I have been asked by the Chancellor of the Exchequer to reply to your question regarding the estimates made of the number of international migrants in (a) London and (b) Wimbledon constituency under (i) the International Passenger Survey and (ii) the proposed Labour Force Survey calculation method. (143012)
ONS has recently published material detailing a number of proposed improvements to the methods used to estimate the effect of international migration on population. Both the existing method and the planned improvements make use of the International Passenger Survey (IPS). One of the planned improvements is to use the Labour Force Survey to distribute IPS estimates of international migration into the UK between the constituent countries of the UK, and between government office regions within England. Information on this is available at the following page of the National Statistics website: http://www.statistics.gov.uk/statbase/Product.asp?vlnk=14834.
Under the existing methods, the net effect of international migration on the population of London was to add 396,000 people to the population between mid-2002 and mid-2005. Under the proposed methods, the indicative net effect of migration would be to add 336,000 to London's population over this period.
ONS does not produce migration estimates for parliamentary constituencies.