About 1,000 Pakistani lawyers and political activists have gathered for the start of a cross-country rally to demand the restoration of judges sacked by Pervez Musharraf, the president.
The protest, due to end in Islamabad, the federal capital, on the weekend, aims to increase pressure on Musharraf to step down.
About 1,500 lawyers and activists rallied in Multan on Monday while about 200 protesters demonstrated in the southwestern city of Quetta.
Lawyers have spearheaded opposition to Musharraf since the former army chief tried to dismiss the country's then chief justice, Iftikhar Chaudhry, last year.
Chaudhry and dozens of other judges were dismissed after Musharraf declared emergency rule in November.
"We are out to save the judiciary. We are out to save the country," Mehmood-ul-Hassan, president of the Karachi Bar Association, told the rally as lawyers chanted "Go Musharraf" in a street in the centre of Karachi.
Dubbed a "long march" even though the lawyers will travel in a motor convoy from Karachi to Multan, where the march to Islamabad will officially begin, it is the first major protest the new government will have to contend with.
Both sides have vowed to keep the peace, with the Pakistan government saying that the lawyers have the right to protest, but the possibility of violence cannot be ruled out.
The protest could also trigger even deeper splits in the coalition led by the party of Benazir Bhutto, the assassinated former prime minister, which is seen as dragging its feet on the restoration of Chaudhry and other sacked judges.