CAIRO (AP) — Egypt’s leading democracy advocate Mohamed ElBaradei and top Muslim and Coptic Christian clerics met today with the army chief to discuss a political road map for Egypt only hours before a military ultimatum to the Islamist president was set to expire.

The meeting signaled the military was taking concrete moves toward implementing its plan to replace President Mohammed Morsi, Egypt’s first freely elected leader who came to office a year ago.

Morsi has vowed not to step down in the face of three days of massive street demonstrations calling for his ouster. At least 39 people have died since the protests began on Sunday.

Under a plan leaked to state media, the military would install a new interim leadership, the Islamist-backed constitution would be suspended and the Islamist-dominated parliament dissolved.

The military has said it will implement its plan once its two-day ultimatum to Morsi expires, between 4 p.m. to 5 p.m. today.

Opposition spokesman Khaled Dwoud announced the meeting in a live telephone interview with state television.

ElBaradei is the leader of the main opposition grouping, the National Salvation Front. He was accompanied in the meeting with army chief Gen. Abdel-Fattah el-Sissi by Sheik Ahmed el-Tayeb, grand imam of Al- Azhar mosque, and Pope Tawadros II, patriarch of Egypt’s Coptic Christian minority.

Even as the clock ticked down toward the military’s deadline, Morsi has remained defiant. In a speech late Tuesday night, he vowed not to step down and pledged to defend his legitimacy with his life in the face of three days of massive street demonstrations calling for his ouster.

The looming showdown follows a night of deadly clashes in Cairo and elsewhere in the country.

The bloodshed, coupled with Morsi’s defiant speech, contributed the sense that both sides are ready to fight to the end.

With his political fate hanging in the balance, Morsi demanded in a posting on his official Twitter account late Tuesday that the powerful armed forces withdraw their ultimatum, saying he rejected all “dictates” — from home or abroad. The army said if no agreement is reached between Morsi and the opposition it would intervene to implement a political road map of its own.

In his emotional, 46-minute address aired live to the nation late Tuesday, the Islamist leader accused loyalists of his ousted autocratic predecessor Hosni Mubarak of exploiting the wave of protests to topple his regime and thwart democracy.

“There is no substitute for legitimacy,” said Morsi, at times angrily raising his voice, thrusting his fist in the air and pounding the podium. He warned that electoral and constitutional legitimacy “is the only guarantee against violence.”

The statement showed that Morsi and his Muslim Brotherhood are prepared to run the risk of challenging the army. It also entrenches the lines of confrontation between his Islamist supporters and Egyptians angry over what they see as his efforts to impose control through the Brotherhood and his failures to deal with the country’s multiple problems.

As anti- and pro-Morsi supporters geared up for the fourth consecutive day of mass rallies today, it was clear that Egypt’s crisis has become a struggle over whether a popular uprising can overturn the verdict of the ballot box.

Mahmoud Badr, spokesman for the youth movement behind the latest wave of protests, called on anti-Morsi protesters to demonstrate outside three presidential palaces as well as the Cairo headquarters of the Republican Guard, an army branch tasked with protecting the president, his family and presidential palaces. Morsi is thought to have been working at the Republican Guard headquarters since the start of the protests.

Badr also called on the army to place Morsi under arrest for his alleged incitement to civil war.

“Today is the day of decisiveness,” Badr said at a news conference today.

Morsi’s opponents say he has lost his legitimacy through mistakes and power grabs and that their turnout on the streets over the past three days shows the nation has turned against him.

On Tuesday, millions of jubilant, chanting Morsi opponents again filled Cairo’s historic Tahrir Square, as well as avenues adjacent to two presidential palaces in the capital, and main squares in cities nationwide. After Morsi’s speech, they erupted in indignation, banging metal fences to raise a din, some raising their shoes in the air in a show of contempt. “Leave, leave,” they chanted.

The president’s supporters also moved out in increased marches in Cairo and other cities, and stepped up warnings that it will take bloodshed to dislodge him. While Morsi has stuck to a stance that he is defending democracy in Egypt, many of his Islamist backers have presented the fight as one to protect Islam.

On Monday, the military gave Morsi an ultimatum to meet the protesters’ demands within 48 hours.