Cheering activists and lawyers marched on the Pakistani capital today to protest outside parliament, defying a government ban and hundreds of arrests nationwide.
Former Prime Minister Nawaz Sharif and the lawyers are demanding President Asif Ali Zardari keep his promise to restore independent judges removed in 2007 by former President Pervez Musharraf.
Mr Sharif is also angry over a Supreme Court decision last month that barred him and his brother from elected office. After the ruling, the federal government dismissed the Punjab provincial administration led by Mr Sharif's brother, stoking popular anger at Mr Zardari.
The lawyers, Mr Sharif's party and other small groupings say they will remain in Islamabad until their demands are met. The government has banned protests in much of the country and arrested more than 360 activists.
Despite the crackdown, several hundred political party workers set off for Islamabad from the southern cities of Quetta and Karachi in convoys of buses and private cars, waving flags and cheering.
Earlier in Karachi police arrested around 60 activists around the city and outside the high court, where they were planning to leave for Islamabad.
The arrests reminded many Pakistanis of similar moves against many of the same activists by Mr Musharraf in 2007 - clampdowns that dramatically reduced his popularity, ushered in the new government, and contributed to his ouster the following year.
The growing political unrest is raising the spectre of a possible military intervention in a nuclear-armed nation prone to army coups.
Mr Zardari, the widower of assassinated former Prime Minister Benazir Bhutto, has tried to rally Pakistanis behind the fight with Islamic extremists. Mr Sharif is considered closer to Islamic parties and conservative factions less inclined to support the West.
Protesters have pledged a peaceful march, but Mr Sharif has used words like "revolution" and other harsh terms in recent speeches, prompting the government to warn him against committing sedition.
Information Minister Sherry Rehman said the rallies were banned to "avoid bloodshed in the streets." While acknowledging her party had staged similar rallies in the past, she insisted that "we never called to raise the flag of rebellion."
The ruling party has restored most of the judges fired by Mr Musharraf, but a few, including a former Supreme Court chief justice, have not regained their seats.
Mr Zardari is believed to fear that those judges could move to limit his power or reopen corruption cases against him that were dropped by Musharraf when the former general was seeking to forge a political alliance before last year's elections.