David Simmonds is the Member of Parliament for the constituency of Ruislip, Northwood and Pinner which has an electorate size of 72,816 voters. This constituency is -0.50% smaller than the average electorate size, which is 73,181. Ruislip, Northwood and Pinner is in the ceremonial county of London (Harrow and Hillingdon), part of the London region.