Thousands of lawyers have started rallies and protests across Pakistan to demand the reinstatement of senior judges sacked last year.
Protesters in Karachi chanted slogans against President Pervez Musharraf, who dismissed the judges.
Correspondents say the action is also a test for the new government, which is divided over how to reinstate them.
The lawyers say the protest – named the long march – will reach the capital, Islamabad, later this week.
The marchers are converging on the city of Multan, the official starting point, where they will be joined by deposed Chief Justice Iftikhar Mohammed Chaudhry.
The convoys will then head for Islamabad, making several stops on the way where reception camps have been set up to receive them, offer them drinks and shower rose petals on them.
They will be joined by civil society activists and some political parties.
Sabihuddin Ahmed, the deposed chief justice of the high court in the southern province of Sindh, told marchers in Karachi that Monday, when the pre-march rallies began, was a “historic day”.
“Judges have come out to protect the country and the constitution,” he said.
Correspondents say that about 4,000 activists from various political parties chanted slogans such as “Go, Musharraf, Go!” and “Musharraf is an American dog!”
Security forces were also out in large numbers, but the rally was peaceful.
Lawyers at a similar protest outside the Multan District Courts hung a large effigy of President Musharraf before beating it and setting it on fire.
The president dismissed dozens of judges, including the Supreme Court chief justice, in November when he imposed emergency rule. At the time he faced numerous legal challenges to staying on as president.
The move further enraged lawyers and his political opponents, who were already infuriated over his attempts earlier in the year to sack the Supreme Court chief justice.
After they won the elections, both the Pakistan Peoples’ Party (PPP) and the Pakistan Muslim League – Nawaz (PML-N) promised to restore the judges but they have not agreed on the mechanics of how this should be done.
The PML-N argues that the judges should be restored by an executive order from the prime minister.
But correspondents say that the PPP wants to link the reinstatement of the judges to a major package of constitutional reforms.
The two parties also appear to differ over how to deal with President Musharraf.
PML-N leader Nawaz Sharif has called for his removal and trial for treason, but the PPP appears wary of a confrontation with the president, who has insisted that he has no plans to resign.