The largest alliance supporting ousted president Mohamed Morsi Thursday urged Egyptian expatriates to boycott the presidential polls as they started to cast their votes.
The National Alliance to Support Legitimacy, led by the Muslim Brotherhood from which Morsi hailed, invited loyalists of the deposed president to stage a week of escalating protests under the slogan of "boycott the polls of blood".
Overseas Egyptians in 124 countries will cast their votes from Thursday to Sunday, while the home elections will be held May 26 and 27.
More than 53 million Egyptians out of the country's 94 million population are eligible to vote in the first post-Morsi presidential elections. Of some 600,000 eligible Egyptian expatriate voters, a large proportion is expected to cast their ballots in Arab countries, especially those in the Gulf region.
Ex-military chief Abdel-Fattah al-Sisi, who led Morsi's removal by the military last July, is expected to make an easy win over his sole leftist rival Hamdeen Sabahy in their contest for the country's top post.
Both candidates have made tough statements against the controversial Brotherhood, currently blacklisted by Egypt's interim leadership as a "terrorist group".
Since Morsi's ouster, his loyalists have been facing a massive crackdown as anti-government protests are staged nearly on a daily basis.