ISLAMABAD, Pakistan — An exiled former Pakistani prime minister, Nawaz Sharif, can return, the Supreme Court said in a decision that clears the way for him to run for Parliament and increases political pressure on President Musharraf.

Lawyers for Mr. Sharif, who founded the Pakistan Muslim League–Nawaz and has been living in London, appealed to the country’s highest appellate bench to allow him back into Pakistan, saying the constitution guarantees him the right to return.

“I want to return as soon as possible,” Mr. Sharif, 57, said in a news conference broadcast from London after yesterday’s ruling. “My priority would be to restore democracy in Pakistan. I am not afraid to face more court cases from the government or if the government plans to arrest me on my arrival.” He called for General Musharraf to give up the presidency and his role as army chief. Mr. Sharif was convicted of corruption and treason after he was ousted by General Musharraf in a 1999 military coup and sentenced to 14 years in prison. General Musharraf pardoned him in 2000 under an agreement in which Mr. Sharif was to be exiled in Saudi Arabia for 10 years. Mr. Sharif had been prime minister between 1990 and 1993 and between 1997 and 1999. Lawyers for Mr. Sharif argued that the exile agreement related only to his dealings with the Saudi government and didn’t bar him from Pakistan.

General Musharraf faces the biggest challenge to his rule as opposition parties protest his plan for a second five-year term and Islamic groups denounce his support for the American-led campaign against terrorism. He rejected imposing a state of emergency to quell unrest and said he wants parliamentary elections to be held by January 15. The polls must take place by the end of January.

General Musharraf says he may run in presidential elections that must be held between September 15 and October 15. Pakistan’s national and provincial legislatures vote to elect the president.

“The party leadership is expected to meet in London in the next few days to decide the timing and strategy for the return of Sharif,” Khawaja Asif, a lawmaker from his party who filed the appeal, said in a phone interview. “Ideally, we think he should return before the elections for the president so that he can lead the move to prevent Musharraf from getting re-elected.”

Mr. Sharif was joined in the case by his exiled brother Shahbaz Sharif, a former chief minister of Punjab province, who was also in London. Calls to the former prime minister weren’t answered.

The Sharifs “have the inalienable right to enter Pakistan at any point in time under Article 15 of the Constitution,” the court in Islamabad said in the ruling following hearings by a seven-judge panel headed by Chief Justice Iftikhar Muhammad Chaudhry. “Their entry into Pakistan shall not be restrained, hampered, or restricted” by the government, the court said.

The government said it would comply with the ruling.

The “decision will be taken in its true spirit and action will be taken accordingly,” the government said in a statement. “We have to respect the verdict of the judiciary and its mandate.”

Mr. Sharif yesterday called for General Musharraf to “return the country to full democracy.”

A presidential vote by lawmakers that takes place before Pakistanis choose a new Parliament would allow General Musharraf to seek re-election before opposition parties and Islamic groups have a chance to gain seats. General Musharraf is seeking support for his re-election from lawmakers in Prime Minister Aziz’s Pakistan Muslim League-Quaid-i-Azam.

The court’s ruling “is a major setback to General Musharraf’s desire to be re-elected as the president because Mr. Sharif can pose a serious challenge to him on his return,” Ishtiaq Ahmed, associate professor of international relations at Quaid-i-Azam University in Islamabad, said in a telephone interview.

A former prime minister, Benazir Bhutto, who has lived in selfimposed exile in London and Dubai since 1999 after being accused of corruption in Pakistan, said in an August 6 interview in New York that she is seeking a balance of power between the president and the prime minister.