Egypt's opposition said Sunday it will keep up protests against a referendum on a disputed draft constitution but stopped short of advocating either a boycott or a ``no'' vote less than a week before the ballot.

The opposition was still pushing for Islamist President Mohammed Morsi to cancel the Dec. 15 referendum, saying they reject the process entirely and refuse to call it legitimate.

The referendum over a disputed draft constitution has deeply polarized Egypt and sparked some of the bloodiest clashes between Morsi supporters and opponents since he came to power in June.

In a sign of how jittery the government about holding the referendum, Morsi has ordered the military to maintain security and protect state institutions until the results of the referendum are announced.

The new presidential decree, published in the official gazette, would be effective starting Monday. The military is asked to coordinate with the police on maintaining security and would also be entitled to arrest civilians.

Morsi insists on holding the referendum on schedule. Instead, as a concession to his opponents, he rescinded decrees he issued last month granting him almost unrestricted powers, giving himself and the panel that drafted the constitution immunity from judicial oversight.

The decrees sparked the protests. Opponents said they were issued initially to protect the disputed constitution from numerous court challenges.

Rushing the approval of the constitution in a late night session in the panel further inflamed those who claim Morsi and his Islamist allies, including the Muslim Brotherhood, are monopolizing power and trying to force their agenda into practice.

The opposition sent hundreds of thousands of protesters into the streets, in unprecedented mass rallies for the largely secular groups since they led the popular uprising last year that toppled President Hosni Mubarak.

This prompted protests by Morsi supporters and sparked bouts of street battles that left at least six people dead and hundreds wounded.

Several offices of the Muslim Brotherhood also have been ransacked or torched in the unrest.

The National Salvation Front, an umbrella opposition group of liberal and leftist parties, said at a news conference Sunday that holding the referendum in such an atmosphere would lead to more strife. It called for another mass demonstration on Tuesday.

The front said Morsi and the regime are ``gambling by driving the country toward more violent clashes that are dangerous for its national security.''

In a sign of the continued tension, Misr 25 TV, affiliated with the Brotherhood, announced that an alliance of Islamist groups will hold rival rallies on Tuesday in support of ``legitimacy.''

Senior Brotherhood leaders accuse the opposition of seeking to topple Morsi and undermine his legitimacy.

The draft charter was adopted despite a last minute walkout by liberal and Christian members of the Constituent Assembly. The document would open the door to Egypt's most extensive implementation of Islamic law or Shariah, enshrining a say for Muslim clerics in legislation, making civil rights subordinate to Shariah and broadly allowing the state to protect ``ethics and morals.''

It fails to outlaw gender discrimination and mainly refers to women in relation to home and family. The charter also has restrictive clauses on freedom of expression.

Khaled Dawoud, a spokesman for the National Salvation Front, said the opposition is hoping to continue its pressure to lead Morsi to reconsider holding the referendum ``and give us more time to discuss a new draft.''

``We will try our best so that this referendum doesn't take place,'' he said.

In his announcement a day earlier, Morsi replaced the scrapped decrees with a new one that doesn't give him unrestricted powers, but allows him to give voters an option if they decide to vote ``no'' on the disputed draft charter.

In the new decree, if the constitution is rejected, Morsi would call for new elections to select 100-member panel to write a new charter within three months. The new panel would then have up to six months to complete its task, and the president would call for a new referendum with a month.

The process would add about 10 more months to Egypt's raucous transition, but could answer some of the opposition demands of a more representative panel to write the charter, if the elections are not swept by Islamists.

The opposition has held a sit-in outside the presidential palace since Friday. A rally of a few thousand marched to join them Sunday.

In a nearby area, several hundred Morsi supporters held a rival rally, lining the street and chanting to traffic: ``Islamic Islamic,'' saying that voting day ``will bring stability.'' (AP)