London West was a constituency electing one Member of the European Parliament (MEP) by the first-past-the-post system. It was created in 1979 and abolished in 1999 when it was replaced by the multi-member London Constituency, using a system of proportional representation. European constituencies were formed by the grouping of UK Parliamentary (Westminster) constituencies. When London West was created in 1979 it consisted of eight Westminster constituencies: Acton, Brentford and Isleworth, Ealing North, Feltham and Heston, Hayes and Harlington, Ruislip-Northwood, Southall, Uxbridge.