In October 1965, the Joint Intelligence Committee estimated that even a full trade embargo would fail to cripple Rhodesia's economy due to sanctions evasion enabled by Portuguese Mozambique and South Africa, but suggested that prolonged and severe economic pressure could induce the white electorate to overthrow the government. In early 1966, Prime Minister Harold Wilson made statements that sanctions were working, predicting that the Rhodesian government would soon fall. At the same time, the Foreign Office was feverishly negotiating with the Portuguese Government to participate in the sanctions, which would effectively impose a total blockade on Rhodesia.