Muslim Brotherhood supporters flocked to Cairo's Tahrir Square on Friday to hear Mohamed Mursi speak on the eve of his inauguration as Egypt's first Islamist, civilian president.
The rally's slogan, "Powers of the president", heralds what may prove a prolonged struggle between the Islamists and army generals who have imposed stark curbs on presidential prerogatives before they formally hand over executive authority.
Crowds in Tahrir, the hub of last year's revolt against ousted leader Hosni Mubarak, chanted "Mursi is president of the republic" and waved Egyptian flags with his picture inset.
"A full revolution or nothing. Down, down with military rule," they shouted. "We, the people, are the red line."
The military council that pushed Mubarak aside on February 11, 2011 has supervised a chaotic stop-go transition since then, holding parliamentary and presidential elections, but then effectively negating their outcome to preserve its own power.
Mursi, who attended weekly Muslim prayers at al-Azhar mosque, was expected to address the nation from Tahrir at about 6 p.m. (1600 GMT). He will swear his oath of office at 11 a.m. on Saturday before the Supreme Constitutional Court in Cairo.
The usual venue is parliament, but the same court dissolved the Islamist-led lower house this month in a ruling backed, if not orchestrated, by the army, apparently unwilling to let Islamists control the legislature as well as the presidency.
"Do we accept that parliament is dissolved?" cheerleaders from the Brotherhood's Freedom and Justice Party (FJP) asked the throng in Tahrir. "No," the party faithful thundered back.
Mursi was declared president last Sunday, a nerve-racking week after a run-off vote in which he narrowly beat ex-air force chief Ahmed Shafik, who was Mubarak's last prime minister.
After being sworn in as the first freely elected civilian president of the most populous Arab state, Mursi will give a speech at Cairo University, a presidency statement said.
Hundreds of protesters have been camped out in Tahrir for weeks to press the army to transfer power to civilians.
"I'm here to tell the military council that we, the people, elected parliament so it is only us, the people, who can dissolve it," said Intissar al-Sakka, a teacher and FJP member.
She, like many of the women in Tahrir, was wearing a waist-length "khemar" veil of the kind favoured by Mursi's wife.
The military council has long promised to hand over power to the next president by July 1, but army sources said the ceremony had been postponed, without giving a reason or a new date.
The generals have seized new powers this month, giving themselves veto rights over the drafting of a new constitution, naming a National Defence Council to run defence and foreign policies and decreeing their control of all military affairs.
The army may have won the skirmish over where Mursi takes his oath, but the Brotherhood is likely to wage a protracted campaign to loosen the military's grip on the new Egypt.
Yet it will be vital to keep such tensions in check if Egypt is to overcome economic woes that have seen foreign reserves drop by more than half in the turmoil since Mubarak's fall.
The International Monetary Fund has made a possible $3.2-billion loan conditional on broad political support for the fiscal discipline it would demand.
The Muslim Brotherhood knows it must focus on the economy to stay popular with voters, who gave it much less support in the presidential poll than in the earlier parliamentary election.
Scenes at the presidential palace occupied by Mubarak for three decades encapsulated the rise of an 84-year-old Islamist movement he had banned, constrained and often persecuted.
Bearded men, some in white robes, others in suits, milled around the palace while Mursi held talks on Thursday with the Muslim Brotherhood's supreme guide Mohamed Badie and consulted clerics from the al-Azhar seat of Islamic learning, hardline Salafis and independent evangelical Muslim preachers.
Many seemed dazzled by the grandeur of their surroundings or intrigued to be walking once-forbidden halls of power.
Security guards, still there from the Mubarak era, shook their heads in frank amazement at the bearded conclave.
After the Brotherhood's Badie entered the gates, one remarked: "Good God, these men were in prison before and wouldn't have dared walk past the compound. Look at them now."
Many Egyptians swarmed around outside, hoping to meet the homespun president-elect with grievances and petitions. Security men complained it was hard to impose order because Mursi had given instructions that people should not be turned away.
After the talks, Mursi's Islamist visitors at the palace in Cairo's Heliopolis district broke a daylong fast with hundreds of takeout meals in cardboard boxes hauled in by palace guards from an army-owned local restaurant – one of the many commercial interests developed by the military over the decades.
The military, the source of every previous president in the Arab republic's 60-year history, runs business enterprises accounting for an estimated one third of the economy.
It does not intend to jeopardise the $1.3-billion a year it receives in military aid from the United States to back Egypt's 1979 peace treaty with Israel, widely criticised by Islamists.
Mursi has said he will respect Egypt's international obligations and does not want to take the country back to war.