CAIRO — Egypt’s interim president swore in a new cabinet on Tuesday that was dominated by liberal and leftist politicians, sweeping away the brief era of Islamist political rule built by the country’s deposed president, Mohamed Morsi.

Not one of the 34 cabinet members belongs to the Muslim Brotherhood, the 80-year-old Islamist movement that propelled Mr. Morsi to the presidency a year ago, or to any other Islamist party. The cabinet does include three women and three Coptic Christians, making it slightly more diverse, in some respects, than Mr. Morsi’s cabinet.

Egypt’s defense minister, Gen. Abdul-Fattah el-Sisi, who has emerged as the country’s de facto leader since Mr. Morsi’s ouster two weeks ago, added the title of deputy to the prime minister to his portfolio, though the specific powers it carried remained vague.

Even as analysts credited some of the ministers for their competence and for bringing badly needed expertise to Egypt’s escalating economic crisis after a year of mismanagement, the composition of the cabinet exposed it to the same criticisms once heaped on Mr. Morsi: that he excluded his opponents from governing and, in the process, demolished any sense of political consensus.

That seemed likely to widen the political fissures that appeared during Mr. Morsi’s presidency and after his ouster, as his supporters took to the streets, vowing to remain until he was released from custody and restored to his post, a demand that was echoed by the Brotherhood.

“In this political scene, they are sending a signal that says, ‘We won and you lost,’ ” said Moataz Abdel Fattah, a political economist at Cairo University.

A spokesman for Adli Mansour, Egypt’s interim president, denied Tuesday that anyone had been “excluded” and said that positions had been offered to members of the Brotherhood and the ultraconservative Islamist Al Nour Party.

But a Brotherhood spokesman, Gehad al-Haddad, said the party was not offered any posts. At the same time, he made clear that the Brotherhood was unwilling to take part, saying, “The whole thing is illegitimate.”

In a statement, Al Nour, which initially blessed the military takeover and called for a purely technocratic government, said the new government’s partisan makeup was a “repetition of the same mistake they blamed the former government for.”

“The policy of monopoly and the exclusion of others,” the statement continued, “deepens the state of division, confusion and instability.”

The formation of the government is part of a military-led transition plan that is supposed to lead to parliamentary elections within six months. The interim prime minister, Hazem el-Beblawi, a respected 76-year-old economist, faces an economy in free fall, deepening security challenges in the Sinai Peninsula and elsewhere, and a drop in tourism that has choked off a critical source of foreign currency.

At the same time, his government has received critical aid, including from gulf Arab states that provided nearly $12 billion after Mr. Morsi’s ouster. This week, the new finance minister said the financial assistance might allow the government to put off negotiations for an aid package from the International Monetary Fund, as well as the painful cuts in subsidies that the loan would require.

Analysts said questions about the government’s legitimacy would depend on Mr. Beblawi’s ability to deliver results quickly to a frustrated public and prove that his government is independent from General Sisi, who brought it to power.

The widespread perception that Egypt’s sprawling state bureaucracy had stopped cooperating with Mr. Morsi means that the new government will face even harsher scrutiny than its predecessor, analysts said.

“These people came in on top of tanks,” said Emad Shahin, a political scientist at the American University in Cairo. “It is not an inclusive government.” At the same time, he said, the government will most likely face fewer obstacles because of “a will from the military and certain regional powers.”

“People wish this government to succeed, unlike the previous one,” Mr. Shahin said.

Several ministers who had served under Mr. Morsi’s widely criticized cabinet returned to their posts. Despite frequent blackouts before Mr. Morsi’s ouster, the electricity minister kept his job, as did the interior minister, Mohamed Ibrahim, whom rights advocates criticized as having done nothing to overhaul security services that are notorious for abuse accusations.

Other appointments, though, seemed to indicate a willingness to try something new. Kamal Abu-Eita, a trade unionist known for opposing former President Hosni Mubarak, was chosen as the minister of manpower, and Laila Iskander Kamel, a community organizer who has worked with Cairo’s garbage collectors, became minister of environment.

Analysts also noted that Mr. Beblawi, who served in a previous government after Mr. Mubarak was deposed in 2011, had shown some independence from the military when he offered his resignation after the army was accused of killing protesters.

In a book he wrote about his time in government, Mr. Beblawi described the shock of the killings. “The state didn’t seem to exist, or seemed completely lost,” he wrote. The head of the armed forces, which was ruling Egypt at the time, refused to accept the resignation, Mr. Beblawi said, so he returned to work for a few weeks before stepping down.

Tuesday’s swearing in of the cabinet, broadcast live on state television, was eclipsed by clashes in Cairo early in the day between Mr. Morsi’s supporters and riot police officers that left at least seven people dead and hundreds wounded. The fighting, the worst in days, accentuated the challenges facing the new government as Mr. Morsi’s Islamist supporters appeared to escalate their campaign to reinstate him.

His supporters had largely confined themselves to a central encampment since June 8, when soldiers and police officers fired on a pro-Morsi demonstration, killing more than 50 people. But late Monday, they ventured out, snarling traffic in some of the city’s busiest roadways before the police responded with force.

The government’s legitimacy “is going to be very hard to measure,” said Zaid al-Ali, a Cairo-based constitutional expert with the International Institute for Democracy and Electoral Assistance. “Under normal circumstances, the government would be accountable to the people, through elections and the media,” he said. “Now there is no parliamentary institution. The only institution that can hold government accountable is the people, through demonstrations.”

“Legitimacy,” he said, “is hanging by a thread.”