They do not know and they do not care. But Spanish voters will this Sunday be asked to deliver their verdict on the new European Union constitutional treaty, launching a fraught 18-month political process that will have a profound effect on the EU's future.

José Lús Rodrguez Zapatero, Spain's socialist prime minister, hoped the poll would be a showcase of his country's European fervour. Instead, the referendum threatens to highlight how remote the EU has become from its citizens' lives.