The information requested falls within the responsibility of the UK Statistics Authority. I have asked the authority to reply.
Letter from Karen Dunnell:
As National Statistician, I have been asked to reply to your recent Parliamentary Question asking for an estimate of the number of people in Darlington constituency whose income rose following the introduction of the national minimum wage. (275750)
Estimates for the number of jobs paid below the national minimum wage by Parliamentary Constituency are not available.
For the UK as a whole, the number of employee jobs paid below the 1999 national minimum wage in 1998 was 1,280 thousand (6 per cent), in 1999 it was estimated at 490 thousand jobs (2 per cent).
A guide to measuring low pay and associated articles can be found on the National Statistics website at: