CAIRO — Shaking off years of political apathy, Egyptians today began voting in their nation’s first parliamentary elections since Hosni Mubarak’s ouster, a giant step toward what many in the country hope will be a democratic Egypt after decades of dictatorship.

The landmark election has already been marred by turmoil in the streets, and the population is sharply polarized and confused over the nation’s direction. Still, the vote promises to be the fairest and cleanest election in Egypt in living memory, and long lines outside polling centers early in the day pointed to a respectable turnout.

The Muslim Brotherhood, Egypt’s largest and best organized group, along with its Islamist allies are expected to do well in the vote, which has been a source of concern for secular and liberal Egyptians eager to keep religion and politics separate.

Voters stood in long lines outside some polling centers in Cairo well before they opened at 8 a.m. local time, a rare sign of interest in political participation after decades of apathy created by the mass rigging of almost every election.

The last parliamentary vote held under Mubarak, who was forced to step down in February after an 18-day uprising, was in November and December last year. That vote was heavily rigged, and Mubarak’s then-ruling party won all but a handful of seats.