CAIRO — President Mohamed Morsi on Sunday ordered Egypt’s Islamist-dominated Parliament back in session, boldly defying the military leaders who had disbanded the body just a month ago.
The generals went into an emergency session within hours of the decree. The official Middle East News Agency said the generals met to ‘‘review and discuss the consequences’’ of the decision but took no immediate action.
Morsi’s surprise move threatens to thrust the country back into a period of instability and violence, 17 months after the ouster of Hosni Mubarak.
According to the official news agency, Morsi reversed the June 15 annulment of Parliament by the military council, which had been ruling the country until he took office late last month, and ordered lawmakers back to work.
A majority of the legislators are members of the Muslim Brotherhood’s Freedom and Justice Party — to which Morsi belongs — or other Islamist groups.
‘No one is going to dismiss Morsi as a figurehead now.’
Morsi also called for parliamentary elections to be held within 60 days of the approval of a new constitution, which is expected later this year.
The decree is considered pivotal by many observers, who have been waiting to see how the fledgling government would respond to the military council’s grab of executive powers on the eve of the presidential election.
Just a week after being sworn in, Morsi has answered with a direct challenge to the generals, signaling that the unfolding power struggle between the armed forces and the once-banned Muslim Brotherhood would not be a one-sided fight.
‘‘No one is going to dismiss Morsi as a figurehead now,’’ said Shadi Hamid, director of research at the Brookings Doha Center in Qatar.
‘‘They had to do something to fight back and gain the momentum,’’ Hamid said. “Assuming it wasn’t pre-negotiated [with the military], and it doesn’t look like it was, it’s certainly an aggressive first move.’’
The decree further confuses Egypt’s tumultuous transition from dictatorship to democracy just one week before a planned visit to Cairo by Secretary of State Hillary Rodham Clinton. Morsi’s gambit could mark the start of a prolonged game of brinksmanship between an entrenched military and a government with popular support.
Morsi’s opponents were quick to accuse him of overreaching.
‘‘The Egyptian Army now is responsible before god and history and the people to protect the law and the constitution,’’ wrote independent Parliament member Muhammed Abu Hamed by Twitter.
But the president’s supporters hailed the decree.
Mohamed Saad Katatny, head of the dissolved Parliament, said in a statement that the legislative body would try to hold a session as soon as possible.
‘‘Which is constitutionally stronger, a president elected by the people’s free will? Or a group who wants a military rule,’’ party chairman Essam el-Erian said via Twitter. ‘‘The armed forces are not responsible for legitimacy; the people are.’’
Several hundred Morsi supporters gathered in Tahrir Square on Sunday night to celebrate his decision. The square was the epicenter of the revolt that toppled the Mubarak regime on Feb. 11, 2011.
Few can predict where the standoff will head next. Given the profound disarray of Egypt’s governing institutions, few can even say who had the authority to arbitrate.
The military dissolved Parliament after a June 14 ruling by the Supreme Constitutional Court that one-third of the members of the lower house had been elected unlawfully. The court is expected to meet Monday to discuss Morsi’s decree.
The June ruling was a significant setback for Morsi’s Freedom and Justice Party, which had just under half of the seats in Parliament.
The judges are appointees of the Mubarak era and are widely assumed to have acted with the blessing, if not the prodding, of the generals.
The next day, in addition to dissolving the Parliament, the military council took sole control of its own budget and a range of national security prerogatives.
Morsi’s decree coincided with a visit to Cairo by Deputy Secretary of Defense William Burns, who said Washington would help jump-start Egypt’s ailing economy.
Burns delivered a message from President Obama, assuring Morsi of America’s commitment to a ‘‘new partnership’’ with Egypt.
‘‘Egyptians know far better than we do that their aspirations are not yet fully realized,’’ Burns told reporters after meeting with Morsi. ‘‘But they can count on America’s partnership on the complicated road ahead.’’
The White House officials said Obama hopes to meet with Morsi during the United Nations General Assembly meetings in New York in September. Obama also invited Morsi for talks in the White House in September, Egypt’s state television said.
According to Hamid, Morsi may have created an opening for a solution that would serve both parties.
Reseating the old Parliament would give Morsi an invaluable legislative boost as he struggles to form his government. At the same time, ensuring relatively quick elections would give the military the new Parliament it craves for the longer term.
The two sides could be dancing toward some kind of settlement, Hamid said. ‘‘The Brotherhood makes an aggressive move, the military reacts, and then they sit down and negotiate something,’’ he said. ‘‘I think it was a good first move. At least something is going to happen now.’’
Morsi came to power after narrowly defeating Mubarak’s last prime minister, Ahmed Shafik, in the runoff last month. Declared the winner June 24, he symbolically took the oath of office five days later at Tahrir Square.
He took the formal oath the next day before the Supreme Constitutional Court and again at Cairo University before hundreds of his supporters, including many of the dissolved Parliament’s members.
In his inauguration speeches Morsi hinted at his displeasure over Parliament’s dissolution and his own diminished powers, pointedly seating its former leader, Katatny, in the front row during the Cairo University ceremony.
The Brotherhood held nearly half the seats in Parliament and has dreamt of political power for most of its 84 years.