Cairo: An Egyptian constitution drafted by Islamists is expected to be approved in a referendum on Saturday after the charter, which opponents say will create deeper turmoil, won approval in a first wave of voting a week ago.
The oppositions have already cried foul, saying a litany of abuses means last Saturday's ballot, involving about half the electorate, should be re-run. But the committee overseeing the two-stage vote said their investigations showed no major irregularities that would invalidate the process.
Islamist supporters of President Mohamed Morsi, who was elected in June, say the constitution is vital to moving Egypt towards democracy two years after Hosni Mubarak was overthrown in a popular uprising. They say it will help restore the stability needed to fix an economy that is on the ropes.
If the basic law is passed, a parliamentary election will be held in about two months.
Polling stations open at 8 a.m. (0600 GMT) and close at 7 p.m. (1700 GMT), though voting is likely to be extended as it was last week. Unofficial tallies are likely to emerge within hours, but the referendum committee may not declare an official result for the two rounds until Monday, after hearing appeals.
The opposition says the constitution is divisive and accuses Morsi of pushing through a document that leans towards his Islamist allies and ignores the rights of Christians, who make up about 10 percent of the population, as well as women.
"I see more unrest," said Ahmed Said, head of the liberal Free Egyptians Party and a member of the National Salvation Front, an opposition coalition brought to together after Morsi expanded his powers on Nov. 22 and then pushed the constitution to a vote.
Citing what he said were "serious violations" on the first day of voting on Dec. 15, he said anger against Morsi and his Islamist allies was growing: "People are not going to accept the way they are dealing with the situation."
Deadly violence marred the build up to the vote. At least eight people were killed in protests outside the presidential palace in Cairo earlier this month.