SANA, Yemen — The Houthi rebels in Yemen, who effectively forced the country’s president and cabinet to resign last month, announced on Friday that they intend to dissolve Parliament and take control of the country, which does not now have a functioning government.

Houthi officials said the plan would be put into effect quickly, but they conceded that the process might take weeks to complete. They said they would name a national council to replace the Parliament, which would in turn choose a committee to select a new president.

“The revolutionary movement has always been quick — it won’t take that long,” said Ali al-Imad, a member of the Houthi political bureau. “It’s not important when, so much as that we now have a political road map.”

The apparent power grab by the Houthis threatens to further destabilize a country whose previous government had been a significant American ally in the fight against Al Qaeda, which has a major presence in the impoverished country. It may also worsen Yemen’s relationship with its wealthy northern neighbor, Saudi Arabia, which already has cut off badly needed aid to Yemen because of the growing power of the Houthis, who are believed to be financed by Iran.

Yemen has been without formal leadership since Jan. 22, when President Abdu Rabbu Mansour Hadi and his entire cabinet abruptly resigned. The Houthis had surrounded the presidential palace and effectively put Mr. Hadi under house arrest. An agreement the two sides reached to ease the crisis and overhaul the government swiftly fell apart, leading to the resignations.

The Houthis mainly belong to a Shiite Muslim sect, the Zaydis, who make up nearly one-third of the country’s population and are dominant in the north. The Houthis are anti-American, but they are even more opposed to Al Qaeda, whose regional affiliate is powerful in the Sunni tribal areas of Yemen, particularly in the oil-rich east and south.

The plans for a new government, decreed unilaterally by the Houthis in the name of their “revolutionary committees,” were announced at a meeting of many of their leaders and officials at a government building, the Republican Palace.

The announcement came after the apparent collapse on Thursday of talks among the Houthis and Yemen’s many political parties that were aimed at forming a government to replace Mr. Hadi and his cabinet. Houthi militiamen closed off a wide area of the city around the palace on Friday, including Tahrir Square, the focus of many antigovernment demonstrations in the past.

“People have expectations, and we’re trying to fulfill those expectations,” said Leyla Lutf, a top official of the Arab Spring party, which is aligned with the Houthi-led revolutionary committees. She, too, was unsure how long the new process would take, but she said, “When you know the target, you know how to reach it.”

Houthi leaders portrayed the plan for a new government as the product of a consensus among Yemen’s political factions. When it was announced, a spokesman, Jamal Asodi, said the new government would be “based on the Constitution,” but he added, “so long as it does not conflict with the revolution.”

Abdul Karim al Khiwani, a prominent dissident journalist and Houthi supporter, said that “all walks of life” were represented in the revolutionary committees and that only “one or two” of Yemen’s parties opposed the new plan.

One of those opposed is Islah, an important Sunni Islamist party whose reluctance to agree on a presidential committee with other parties was one of the reason the talks failed Thursday.

The unilateral declaration by the Houthis was also likely to be unpopular in southern Yemen, where separatist sentiment is strong, and in tribal areas where the Yemeni government and the Houthis have tried to win Sunni loyalties away from extremist groups like Al Qaeda in the Arabian Peninsula. Northern and southern Yemen were separate, often antagonistic, countries from 1968 to 1990.

Criticism of the Houthis’ action came quickly on Friday. “This is a clear coup against democracy and constitutional legitimacy,” said Majid Alshadadi, 35, an education ministry official from Ibb Province. He accused former President Ali Abdullah Saleh, who has allied himself with the Houthis, of being behind the move. “This is the beginning of the end of the Houthis,” he said.

The plan calls for the Houthis’ revolutionary committees to select a 551-member national council. The council will take the place of the national Parliament, which continued to meet despite questions about its legality even before Mr. Hadi resigned. The new national council is to choose a five-member presidential commission, which in turn would choose a new president, according to the statement that Mr. Asodi read at the palace.

“Change will come quickly,” Mr. Khiwani said, adding that the revolutionary committees began meeting immediately after the announcement on Friday, and that senior security officials were present. Even so, he said, it may take weeks to establish the new government and name a president.

Yemen faces a serious economic crisis and is running out of money. Just how much longer it can continue paying public-sector workers is an open question, and a worrisome one because the government is the largest employer in the capital.

“To some extent, things are kind of on pause right now, and running on autopilot,” said April Longley Alley, the senior Yemen analyst at the International Crisis Group. “The Houthis have a pretty solid control over the security situation in Sana. It’s been quiet for a couple weeks. But that can’t go on forever without a political compromise.

“The Houthis know that, and other groups do, too,” she continued. “They’re going to start butting up against some hard fiscal realities.”

The Houthis’ television station, al-Maseera TV, broadcast an announcement Friday evening calling on members of the revolutionary committees to celebrate the new plan by setting off fireworks, which soon lit up the skies over the capital.

NY Times