National Insurance Number Allocations to Overseas Nationals entering the UK (previously Migrant Workers Statistics) / DWP, 24 July 2007
Background
PDF - http://www.dwp.gov.uk/asd/asd1/niall/niall_background.pdf
Full report
PDF - http://www.dwp.gov.uk/asd/asd1/niall/niall_report.pdf
First release
PDF - http://www.dwp.gov.uk/asd/asd1/niall/niall_first_release.pdf