The UK House of Lords has adopted amendments to the European Union (Withdrawal) Bill that would make the conclusion of a withdrawal agreement contingent on parliamentary approval. It is not at all clear which, if any, of the Lords amendments will survive in the House of Commons, and we may not find out for a while. It may be premature to conclude that Parliament is now fully in charge of the Brexit process. What the amendments show, however, is that Parliament can assert control if it chooses to do so.