Cairo - Egyptian President Mohamed Morsi and his allies refused to back down on their call to reinstate the disbanded Islamist-dominated Parliament Monday, ignoring a veiled threat from the military and a rebuke from the country's highest court and ordering lawmakers to take their seats today at noon.

The deadline marked the second day of escalating tensions in the standoff between the newly elected Morsi, a member of the long-banned Muslim Brotherhood, and the vestiges of the former Mubarak regime, which still control Egypt's military and judiciary.

"It's quiet for now, but wait until tomorrow," said a kiosk vendor outside the still-quiet Parliament Building on the evening before the expected showdown.

No extra troops were in evidence around the facility and the streets were quiet except for Cairo's chronic horn blowing. Police in regular uniforms manned the gates and sat in groups on surrounding sidewalks.

A week into his term, Morsi has quickly brought to a head the central dispute between the factions, the abrupt dismissal of the first post-revolution parliament by the then-ruling military council and the Supreme Constitutional Court.

As Egypt struggles to find its footing as the Arab world's newest - and largest - democracy, Morsi's aggressive opening moves make it more likely that public confrontations between the sides will follow. The confrontation emerges just days before an expected weekend visit by U.S. Secretary of State Hillary Rodham Clinton.

In Tahrir Square, the center of last year's historic popular uprising, Morsi supporters on Monday waved signs cheering Morsi's actions.

There was a modicum of ceremonial civility Monday, when Morsi appeared at a military graduation ceremony as the guest of Field Marshal Mohammed Hussein Tantawi, leader of the Supreme Council of the Armed Forces. The two watched the marching cadets with a few exchanged words and a few laughs.

But outside the gates, both sides dug in on the standoff that began with Morsi's decree Sunday annulling the Constitutional Court's ruling and ordering Parliament's return.

The court responded Monday with a warning that its June 14 ruling against the legislature was "final and binding," according to state television reports. The military council on Monday warned Morsi to adhere to the court's ruling and respect the constitution. The statement left little doubt that Morsi's decree caught the generals off-guard and that the move was not part of a negotiated power sharing deal.

In the meantime, other participants in Egypt's fractured political scene warily staked out positions on what could be the next defining dispute in the country's struggles to emerge from decades of dictatorship.

Brotherhood supporters, and some members of the coalition of youth activists that helped sparked the Tahrir uprising, cheered Morsi for standing up for a legislature they view as freely and fairly elected.

But several candidates from the just-completed presidential election deplored the president's action as a power grab. Even some Mubarak opponents, liberals and secularists, saw Morsi's actions as an end-run that threatened the country's judicial integrity.

"The executive decision to overrule the Constitutional Court is turning Egypt from a government of law into a government of men," read a tweet from Mohamed El Baradei, the Nobel Prize winning former diplomat who briefly considered a run for the presidency last year.