Egyptians began casting ballots Saturday in a two-day presidential run-off that pits a prime minister from former president Hosni Mubarak's era against a Muslim Brotherhood candidate.

Ahmed Shafiq, the former prime minister, is vying with the Brotherhood's Mohamed Morsi to become Egypt's first president since the huge outpouring of anti-government protests that forced Mubarak's to resign last year.

VOA Middle East Correspondent Elizabeth Arrott says voter turnout in Cairo has been lighter than it was during last month's first-round polling.

Arrott reports voters may be disillusioned by the stark differences between the the two contenders.

“There are the two candidates, Mohamed Morsi of the Muslim Brotherhood and Ahmed Shafiq, the last prime minister of the old regime — kind of a polarizing choice which I think is a lot less joyful than what people had the first time around when you had 13 candidates and it all seemed so wide open.”

The election went ahead as scheduled despite a week of intense political turmoil in Egypt, triggered by a Supreme Constitutional Court ruling that overturned a legal effort to strike Shafiq from the ballot since he held a senior post under Mubarak.

The justices – holdovers from the Mubarak era themselves – also cited legal problems with the last round of parliamentary elections and dissolved the current Islamist-led parliament. That returned effective control of the country to the interim military administration that took over following Mubarak's ouster.

Some leading Islamists contend the court ruling justified what amounts to a defacto coup by the ruling military council. But the council said the presidential runoff would go ahead as planned.

Speaking to his supporters in Cairo Thursday, Mr. Shafiq called the court ruling “historic” and urged all Egyptians to take part in the polls. The Muslim Brotherhood said the court's decision indicated that Egypt is heading into “very difficult days, that might be more dangerous than the last days of Mubarak's rule.”

Protesters angered by the court ruling took to the streets in Cairo and Alexandria Friday. Thousands marched to Cairo's Tahrir Square, directing their wrath at Mr. Shafiq, suspicious the former prime minister remains part of a larger plot.

Meanwhile, a campaign urging voters to spoil their ballots, in a bid to show disapproval with both candidates, picked up steam in recent days. Other Egyptians are simply boycotting the vote.

Unofficial results from Saturday and Sunday's polling are expected early in the week. The announcement of the winner is set for Thursday.