Poland's president has revealed 15 questions Polish voters could face in a referendum on whether to change the constitution — including whether to strengthen the president's powers and protect Poland's membership in the European Union and NATO.

President Andrzej Duda has long called for amending the constitution and has set Nov. 10-11 as the dates for a referendum. But he had so far been vague about the changes he sought.

After a meeting Tuesday of the National Development Council, an advisory body, Duda presented 15 questions being considered, though said they are still up for discussion.

The first is whether voters want a new constitutional at all. Other questions include whether to enshrine new, lower retirement ages — 60 for women, 65 for men.