In accordance with MacDonald's White Paper of May 1939, the British High Commissioner is empowered to severely restrict further land acquisitions by Jews. Mandate Palestine is divided into two zones: Zone A (about 63% of Palestine) and Zone B (about 32%). In Zone A, Arab-owned land cannot be sold or encumbered to Jews; in Zone B, the same prohibition applies, except if the transaction is permitted by the High Commissioner. In the remaining 5% of the country, or “free zone” (the most fertile areas), no restriction is imposed. Despite the stringency of this unprecedented measure, many instances of circumvention are uncovered in the years preceding the termination of the Mandate.