Thousands of pro-government and opposition protesters are holding rival rallies in Cairo for and against a controversial constitutional referendum proposed by Egyptian President Mohamed Morsi.
Leftists, liberals and other opposition groups called for Tuesday's marches to the presidential palace to protest against the hastily arranged referendum planned for Saturday.
Al Jazeera's Sherine Tadros, reporting from the anti-Morsi rally, said that thousands of protesters have joined the rally after at least six opposition marches taking place nearby joined the crowd.
Some of the protesters have managed to breach the concrete barriers intended to keep them away from the presidential palace.
"Most of them just walk right by the concrete barriers...and they're right by the walls of the palace," said Tadros.
"The situation is still pretty calm - it's actually quite a festive atmosphere," said Tadros, adding that films showing why people should vote "no" on the constitutional referendum will be projected on the palace walls.
"The Republican Guard haven't reacted. The relationship between the protesters and the Republican Guard up until this point has been quite amicable," said Tadros.
The centre-right Islamists who dominated the body that drew up the constitution have urged their followers to turn out "in millions" in a show of support for the president and for a referendum they feel sure of winning.
Al Jazeera's Hoda Abdel-Hamid, reporting from the pro-Morsi rally in the Nasr City neighbourhood, said speaker after speaker has been taking the stage, calling for the constitution to go through.
"This rally is probably much bigger than what the organiser expected," said Abdel-Hamid, who was at one of three pro-Morsi rallies taking place in Egypt..
"Here, people do support President Morsi. Here, people do say that they are behind the constitution," said Abdel-Hamid.
"For them, the constitution brings stability to the country and economic recovery. And a lot of people here will tell you that their lives have been at a standstill since the revolution back in 2011."
Critics of the draft constitution say it disregards the rights of women and ignores personal freedoms.
The opposition, stubbornly calling for the referendum to be delayed, was still trying to decide late on Monday whether to boycott the vote or rally Egyptians to vote "no" to the draft.
Egypt's political crisis began on November 22 when Morsi issued a decree expanding his powers, granting himself immunity from judicial oversight or challenge. The decree, which he later withdrew, sparked mass demonstrations.
Seven people were killed and hundreds wounded last week in clashes between the supporters of Morsi's Muslim Brotherhood and opponents besieging the graffiti-daubed presidential palace.
A vital $4.8bn International Monetary Fund loan to Egypt has delayed until next month, Egypt's Finance Minister Mumtaz al-Said said on Tuesday, intensifying the political crisis gripping the country.
The elite Republican Guard has yet to use force to keep protesters away from the palace, now ringed with tanks, barbed wire and concrete barricades, but a decree issued by Morsi late on Sunday gives the armed forces the power to arrest civilians during the referendum and until the announcement of the results.
The head of the Egyptian military called for a "national dialogue" to be held on Wednesday in an attempt to resolve the constitutional crisis, a military source said.
Defence Minister Abdel Fattah al-Sisi is calling for all sections of the people to convene a national dialogue at the
Olympic Village tomorrow," the military source told Reuters.
The Egyptian president insists on holding the referendum on schedule, despite concerns over who will monitor the vote. Several groups of judges have said they will not oversee the referendum, as is customary for judges in Egypt.
Judges of the nation's administrative courts announced on Monday they were conditionally lifting their boycott of the vote, but they said their supervision of the process was conditional on bringing an end to the siege of the Supreme Constitutional Court by Morsi's supporters.
In exchange for their supervision, they also demanded assurances that authorities would crack down on vote canvassing outside polling stations and offer life insurance policies to the judges.
Leftist politician Hamdeen Sabahy, one of the most prominent members of the National Salvation Front opposition coalition, said Morsi was driving a wedge between Egyptians and destroying prospects for consensus.
"The road Mohamed Morsi is taking now does not create the possibility for national consensus," Sabahy said.
If the constitution was passed, he said: "Egypt will continue in this really charged state. It is certain that this constitution is driving us to more political polarisation."
The National Salvation Front also includes Nobel Peace Prize laureate Mohamed ElBaradei and former Arab League chief Amr Moussa.
Morsi's decision on Saturday to retract a decree awarding himself wide powers failed to placate opponents who accused him of plunging Egypt deeper into crisis by refusing to postpone the vote on the constitution scheduled for December 15.
"We are against this process from start to finish," Hussein Abdel Ghani, spokesperson of the National Salvation Front, said.