One consequence of Britain's entry to the European Common Market is likely to be an increase in grain production. An unofficial estimate gives the extra acreage needed for corn production as about 5 million by 1980, about 2 million being required from "permanent grassland". The area under most pressure will be the Midlands, and the class of monument most likely to be affected is the deserted medieval village and associated field systems. Further, if livestock is maintained at current numbers, there may well be draining and reseeding of rough grazing land, with consequent threats to many prehistoric sites. The rate of destruction on previously uncultivated land can be calculated at about 400 sites per year for ten years for EEC requirements alone.