The information requested falls within the responsibility of the UK Statistics Authority. I have asked the authority to reply.
Letter from Karen Dunnell, dated February 2009:
As National Statistician, I have been asked to reply to your Parliamentary Question asking how many non-UK nationals were working in Wales in 2008. (258034)
There are an estimated 48 thousand non-UK nationals aged 16 and over in employment in Wales.
The estimate is derived from the Labour Force Survey (LFS) using the latest data available (October-December 2008). It should be noted that the above estimate excludes people in most types of communal establishment (e.g. hotels, boarding houses, hostels, mobile home sites etc). As with any sample survey, estimates from the LFS are subject to a margin of uncertainty.
The figure is derived from the LFS microdata which are weighted using the official population estimates published in autumn 2007. Consequently the estimate is not entirely consistent with the figures published in the monthly Labour Market Statistics First Release, or the migrant workers figures published every quarter, which are weighted using more up-to-date population estimates.