The prime minister made an emotional appeal for a massive turnout in Spain's referendum Sunday on the European Union constitution _ the document's first test at grass-roots level _ saying it will make the continent safer and help fight terrorism. Jose Luis Rodriguez Zapatero concluded campaigning for the referendum on Friday night, saying the constitution was as important for Spaniards as the one they approved for their own country in 1978, restoring a democratic charter three years after the death of Gen. Francisco Franco. The referendum is nonbinding, with Parliament having the final say. "Now we have another historic opportunity and must not squander it," Zapatero told a rally in Madrid. "We cannot miss the opportunity to be protagonists and set the course for all Europeans with a massive 'yes.'" Spain will be the first of at least nine EU countries to hold a referendum on the constitution, designed to streamline the EU's decision-making as the bloc expands eastward, making it more efficient and giving it global clout on a par with its economic might. Both of Spain's main parties back the constitution and it is expected to be approved in the referendum. Campaigning was banned on Saturday, with the day before the vote considered a day of reflection.