HC Deb 03 July 1956 vol 555 c95W
Mr. Pitman

asked the Minister of Labour when the term "dilutees" was first officially used to describe a particular type of workman in the engineering industry; and what this description was intended to imply.

Mr. Iain Macleod

I cannot say precisely when the term was first used, but the word "dilution", in its industrial meaning, was in common use as early as the First World War. The term "dilutees" was used in certain Relaxation of Customs Agreements in the engineering industry dated 1940 to describe and identify workers who were introduced under these agreements to supplement the skilled manpower in the industry.