CAIRO – With their nation’s future at stake, Egyptians lined up Saturday to vote on a draft constitution after weeks of turmoil that have left them deeply divided between Islamist supporters of the charter and those who fear it will usher in religious rule.

The referendum caps a nearly two-year struggle over the post-revolutionary identity of Egypt after the ouster of Hosni Mubarak’s authoritarian regime.

Activists on both sides describe it as a battle over Egypt’s post-revolutionary identity: whether it will move toward a religious state under President Mohammed Morsi’s Muslim Brotherhood and ultraconservative Salafi allies, with Islamic principles limiting rights and clerics having a say over legislation, or one that retains secular traditions and an Islamic character. But many Egyptians said they were mainly looking for stability.

Monitors from opposition parties and rights groups have so far reported a wide range of irregularities in Saturday’s vote. They have not reported any systematic countrywide fraud but reports of violations increased as night fell. In one stark example in the Mediterranean port city of Alexandria, some 1,500 Egyptian women from a liberal-leaning district blocked a main road, claiming a judge prevented them from voting.

Election authorities also extended voting by two hours, to 11 p.m. (4 p.m. EST) because of continued long lines and delays at the polling stations.

Morsi’s supporters say the constitution will help end the political instability that has roiled Egypt since the autocratic Mubarak was overthrown. Some proponents say the draft limits presidential powers and protects against torture and police abuse but others, including clerics preaching from the pulpits of mosques, have taken a more strident line, describing it as a document that champions Islam and denouncing its opponents as nonbelievers.

The president’s opponents say minority concerns have been ignored and the charter is full of obscurely worded clauses that could allow the ruling Islamists to restrict civil liberties, ignore women’s rights and undermine labor unions.

Many also fear the newly empowered Muslim Brotherhood and more ultraconservative Islamists are taking advantage of their current political dominance to adopt a charter that will be nearly impossible to amend.