Egyptian expatriates started Wednesday morning casting their votes in the constitutional referendum, official news agency MENA reported.

About 589,000 Egyptians are expected to go to the Egyptian embassies and consulates overseas to cast their ballots in a voting process scheduled to end on Saturday.

All the involved Egyptian embassies and consulates will be open from 8 a.m. till 8 p.m. local time (0600 GMT till 1800 GMT), so that people can vote before and after work.

Meanwhile, Egyptians at home are to take part in the referendum on the controversial draft constitution Saturday despite the opposition's call for a nationwide protest, urging to postpone the referendum until a consensus is reached.

Morsi has reportedly given the army the power to arrest and called on the civilians to help the police maintain the security for the referendum.

In a related context, some private Egyptian newspapers reported earlier Wednesday that Morsi had decided to run the constitutional referendum inside Egypt in two separated stages, but pan-Arab Al Jazeera TV quoted the head of the Higher Commission for Elections as denying the news.