A procedure introduced by the Single European Act1986 that allows the European Parliament to impede the adoption of proposed legislation by the Council of the European Union; the Maastricht Treaty extended the use of this procedure to cover new areas of policy. It applies when there is a second reading of a draft measure. If the Parliament takes no action for three months after receiving the proposal, it proceeds. However, if, after a second reading, Parliament votes by an absolute majority to reject the measure, this can only be overturned by a unanimous decision of the Council. Compare assent procedure; codecision procedure.