The first and fundamental point is that the Treaty concerns only those matters which have a European element, that is to say, matters which affect people or property in the nine countries of the Common Market besides ourselves. The Treaty does not touch any of the matters which concern solely the mainland of England and the people in it. These are still governed by English law. They are not affected by the Treaty. But when we come to matters with a European element, the Treaty is like an incoming tide. It flows into the estuaries and up the rivers. It cannot be held back.
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— Lord Denning, discussing the Treaty of Rome in his judgment in H.P. Bulmer Ltd v J. Bollinger SA (1974)