Unable to crush street protests Sunday that spilled out of this city and threatened to reach the capital, the Pakistani government announced early Monday morning that it would restore the former chief justice of the Supreme Court and a group of other deposed judges in a major capitulation to opponents. The move reflected the weakening position of President Asif Ali Zardari, a key U.S. ally. Zardari had resisted bringing back former chief justice Iftikhar Mohammed Chaudhry for months, but he faced mounting pressure from a broad coalition of opponents who demanded the reinstatement of Pakistan's independent judiciary and threatened to march on the capital, Islamabad, until Chaudhry was brought back. The decision marked an extraordinary victory for Pakistan's legal community, which has been agitating peacefully for the judges' reinstatement for the past two years, and for Zardari's major political rival, former prime minister Nawaz Sharif. He defied house arrest Sunday to lead supporters in a boisterous protest caravan along the 150-mile route to Islamabad. As word spread early morning Monday that Prime Minister Yousaf Raza Gillani would announce the judges' restoration to office, Pakistani television stations showed jubilant crowds gathering around Chaudhry's house in Islamabad. Celebrations also erupted in the Sharif-led caravan, which was traveling through the night from Lahore. The prime minister made the official announcement at dawn Monday in an address to the nation, saying Chaudhry would be reinstated March 21, and that lawyers and activists arrested in the past week would be freed. "This will restore stability to Pakistan," Athar Minallah, a spokesman for Chaudhry, said early Monday, as analysts suggested the move and other concessions offered by the government might heal the rift between Zardari and Sharif. Pakistan, a nuclear-armed Muslim nation of 172 million, faces a raging Islamist insurgency and a deepening economic crisis. The growing confrontation between Zardari and a coalition of primarily secular opponents has alarmed Washington and raised the prospect of a possible army coup, just one year after Pakistan emerged from a decade of military rule. A spokesman for Sharif's party, the Pakistan Muslim League-N, had said that he expected an official pardon of Chaudhry and the other judges, in accordance with an agreement signed by Zardari and Sharif last year. Muslim League officials had suggested that once the decision was officially announced, they would call off their "long march" to the capital Monday and cancel a long-planned protest. The government had sealed off Islamabad with shipping containers and other barricades late Saturday in an attempt to prevent the marchers from entering the federal government district. But as rumors of Chaudhry's restoration spread, many police barricades were withdrawn from the Grand Trunk Road and hundreds of people joined the procession in towns along the way. Chaudhry and the other judges were fired in 2007 by Pakistan's former military ruler, Pervez Musharraf, because they refused to take an oath under his amended constitution. Zardari had publicly insisted that the judges could not be restored until Pakistan's Parliament had a chance to make broader changes in the constitution. But many Pakistanis and foreign observers believed the president reneged on his pledge to restore them because he feared that the independent-minded Chaudhry would reopen old corruption cases against him and might also overturn many of his actions as president. Zardari's turnabout came after thousands of demonstrators poured into the streets of this leafy capital of Punjab province Sunday, throwing rocks at police and cheering wildly. A wide cross section of Pakistan's political, social and religious sectors joined the day-long protests. As the protests escalated, police first responded with volleys of tear gas. But by mid-afternoon they suddenly withdrew from the streets, while numerous city and provincial officials were reported to have resigned. The swift collapse of authority signaled the end of Zardari's bid to seize control of Punjab, the most politically influential region of the country, and raised serious questions about his ability to remain president. "The present rulers are defaming every norm of democracy, and Zardari is behaving worse than a dictator. We will continue our march until the rule of law is restored," vowed Iqbal Haider before the judges' reinstatement was announced. Haider, a white-haired lawyer, was attorney general under slain former prime minister Benazir Bhutto. Bhutto, a charismatic leader and champion of democracy who was married to Zardari, held power twice and was assassinated in 2007 while planning a political comeback. Her widower took her place as leader of the Pakistan People's Party and pledged to mend fences with her longtime rival, Sharif, but the alliance quickly soured. There was no public appearance or statement Sunday by Zardari, but his new information minister, Qamar Zaman Kaira, told journalists in Islamabad that the government hoped to resolve its differences with the opposition through amicable negotiation. Kaira replaced Sherry Rehman, who abruptly resigned from the post late Friday night after the government temporarily blocked transmission of a major independent news channel. Several members of Zardari's party have defected in the past week, including three members of Parliament. In another sign of the government's weakening grip, key opposition leaders in Lahore, including Sharif and legal dissident Aitzaz Ahsan, began the day under house arrest and ended it leading caravans of chanting supporters through the streets. At dusk, Ahsan addressed supporters by torchlight inside the Lahore High Court compound. Pakistani news media reported that several other opposition leaders, including Sharif's brother Shahbaz and the heads of other political parties, had reached Rawalpindi, a garrison city about 15 miles from Islamabad, and were hiding in private homes waiting to join the marchers and move toward the capital. "The writ of the government has ended. Nobody can stop us from reaching Islamabad," Ahsan told a cheering crowd of lawyers while stirring music played from loudspeakers. As night fell in Lahore, streets that had been full of tear gas and flying rocks during the day became scenes of celebration. People danced, sang and waved banners atop cars and trucks as smiling police watched from the sidelines, their riot gear discarded on the ground. Ice cream and sugar cane sellers came out on the sidewalks and boys set off fireworks. Several police officers said they were relieved to have been pulled back from the protest areas after several hours of tension and violent clashes, and also said they supported the Sharifs. Punjab has traditionally been a stronghold of the Sharif brothers, and Zardari's imposition of central authority last month was extremely unpopular. With Zardari rapidly losing control, officials in Islamabad scrambled to find a way out. Kaira said officials would ask the high court to review its decision last month to bar the Sharifs from politics. But the protesters, flush with success, were in no mood to negotiate. They included hundreds of black-suited lawyers, activists from Sharif's Muslim League, conservative Muslims from the Jamaat-i-Islami religious party, women from civic and human rights groups, followers of former cricket champion and politician Imran Khan, and disaffected members of Zardari's ruling Pakistan People's Party. "We have already achieved success. The whole city has come out to support us, and the government is helpless," said Mohammed Fareed Chaudhry, 55, a lawyer. "We respect and appreciate all the parties and groups that have joined our cause. It is only a matter of hours or days before Zardari will have to leave power."