Protest In Tahrir Square, Cairo
Anti-Mursi protesters chant slogans in Tahrir Square in Cairo. Reuters

The hotly contested popular referendum on the Egyptian draft constitution began on Wednesday for nearly 600,000 Egyptian expatriates, state news agency MENA reported. Just in time, the National Salvation Front, an umbrella opposition party, released a statement telling their supporters that instead of merely boycotting the vote they should vote no on the referendum.

The first round of voting in Egypt will begin on Dec. 15 for 10 governates, including Cairo and Alexandria, MENA reported. A second round for the remaining 17 governates will be held on Dec. 22. The last-minute splitting of the vote was announced on Tuesday night.

The sudden coming together of a greatly disjointed opposition front, which has been rather ineffective at communicating a message, any message, may represent a step forward for anti-Islamist efforts, but the referendum on the constitution is still widely predicted to pass. The opposition is particularly concerned with the dominant Islamist Assembly, which could ignore Christian, secular, or other more pluralistic voices.

The Grand Sheikh at the Al-Azhar mosque, one of Cairo's largest, told the press on Wednesday that participating in the referendum was a "religious duty."

“We want Egypt to be a consensual, constitutional, democratic and modern state,” said the Grand Sheikh Ahmed al-Tayyeb, adding that "all political forces should accept the result of the referendum."

Even if there were a boycott, it would be difficult to tell. "Voter turnout in Egypt is always very low," said Marina Ottoway, a senior associate in the Middle East program at the Carnegie Endowment for Peace. "It's not going to be 90 percent of electorate going to the polls. One of the difficulties will be judging whether there's been a boycott or not. Will it be lower than the normal low in Egyptian politics?"

Protests continued in Cairo and Alexandria on Tuesday night, both for and against the Muslim Brotherhood, Al-Masry Al-Youm reported. Protesters once again stormed the presidential palace in Cairo and broke down a gate, Voice of America said, but by the evening calm had been restored.