CAIRO — Egypt's main opposition alliance called for a "no" vote in Saturday's referendum on a disputed constitution rather than a boycott, hours after President Mohammed Morsi's Islamist-led government forged ahead by starting overseas voting in diplomatic missions for expatriates.
The opposition's decision did not dispel the atmosphere of a nation in crisis, deeply polarized over the referendum that has stoked three weeks of turmoil on the streets.
The opposition still plans more protests, and the country's judges are still on strike over a decree by Mr. Morsi, since rescinded, that placed him above judicial oversight.
The military is inching back into politics. And if the referendum passes, there is potential for even greater upheaval.
There also are growing concerns about the already flailing economy.
Egypt on Tuesday requested a postponement of a $4.8 billion International Monetary Fund loan after Mr. Morsi, fearing a popular backlash at a time of already heightened tensions, suspended a package of tax increases that had been part of a program to reduce the huge budget deficit.
The opposition said it still may boycott the vote starting in Egypt on Saturday if its conditions are not met.
Hamdeen Sabahi, one of the leaders of the opposition National Salvation Front, said at a news conference the alliance would urge its supporters to boycott if judges do not oversee the vote and the state does not provide security at the polls.
The country's major judges' union said Tuesday it would boycott the referendum, abstaining from their traditional role of oversight at the polls.
"The Front decided to call upon the people to go to the polling stations and reject the draft by saying 'no,'" said Mr. Sabahi, a leftist politician who finished a close third in the June presidential election narrowly won by Mr. Morsi. "The people will rally at the polls and have a chance to topple the constitution by saying 'no.'"
The Islamist-dominated constitution-drafting committee rushed through the document in a marathon session last month. Islamists say its approval will restore political stability and allow the rebuilding of the institutions of government.
They say it contains new articles banning many of the human rights abuses that were commonplace under Mr. Morsi's ousted predecessor Hosni Mubarak, whose 29-year regime was ousted in a popular uprising nearly two years ago.
Liberals, secularists, Christians, and other critics say the draft is full of obscurely worded clauses that could give clerics a say over the legality of legislation and allow civil rights to be curtailed by hard-line interpretations of Shariah, or Islamic, law.
They say the 100-member committee tasked to draft the constitution was packed with Islamists and ultraconservatives who ignored other groups' concerns and sped the draft through.
The nationwide referendum initially was scheduled to take place on Saturday, but in a last-minute decree on Tuesday, Mr. Morsi ordered the voting stretched into another round on Dec. 22.
Voting must be overseen by judges, but the powerful judges' union voted Tuesday not to supervise the process, protesting an earlier and now rescinded decree by Mr. Morsi placing him above judicial oversight.
Their absence would throw the legitimacy of the vote into question and thus the legitimacy of the constitution itself.