Sharif's supporters protest court ruling in Pakistan

Meanwhile, Prime Minister Yousuf Raza Gilani told Parliament that the government would ask the Supreme Court to block Sharif's disqualification and postpone the vote in Sharif's district scheduled for Thursday.

The court ruling has exacerbated tensions between Sharif's party, the Pakistan Muslim League-N, and its larger partner in the ruling coalition, the Pakistan People's Party.

Bickering over the restoration of judges ousted by President Pervez Musharraf last year has undermined their young government, whose cooperation is considered key to the U.S.-led war on terror.

A successful move by the government to clear Sharif's path could cool the tensions between the parties.

Scores of angry Sharif backers demonstrated outside the parliament building in Islamabad, while lawmakers from Sharif's party walked out of the National Assembly in protest.

In Sharif's hometown of Lahore, about 600 protesters burned tires in the city center. Hundreds protested in the central city of Multan, where they burned an effigy of Musharraf and one representing the judges he installed.

Sharif party spokesman Sadiqul Farooq said Tuesday that the party would not appeal the Lahore High Court's Monday ruling because it lacks confidence in the judiciary.

However, Law Minister Farooq Naek — like Gilani a People's Party member — said the government would step in and petition the Supreme Court later Tuesday or Wednesday to block the decision.

Information Minister Sherry Rehman said a favorable ruling could also help heal the rift in the coalition.

"We want to keep the alliance intact and we are in contact with our allies. We want the public to know the government stance, that we want to strengthen the democracy," she said.

Sharif, who was deposed by Musharraf in a 1999 coup, is now the most popular politician in Pakistan.