Sharif would seem an unlikely champion of the judiciary.
He had a major dispute with the Supreme Court during his second term as prime minister in the 1990s, which led to the removal of the then chief justice.
But he has made a demand for the restoration of the judges, some of whom remain under house arrest, a main theme of his party's campaign.
"These judges are our heroes," he said. "It is our commitment that we will restore these judges at any cost."
The vote for provincial parliaments and a National Assembly from which a prime minister and a government will be drawn is a three-way race between Sharif, Bhutto and the party that ruled under Musharraf and backs him.
Analysts expect a hung parliament which would likely mean two of the three main parties having to forge an alliance.
In Sukkur, flags and posters of Bhutto's party bedecked walls around the market where Sharif spoke. Some traders didn't even bother closing their shops.
"Why should I close my shop and go to his rally? He's not my leader, I didn't invite him," said Muhammad Abid whose shop is a couple of hundred yards away from the stage where Sharif spoke.
"I can't vote for someone who ran away instead of facing the courts," he said, referring to Sharif's exile to Saudi Arabia in 2000, a year after he was ousted.
He was allowed to leave and escape a prison term in exchange, the government says, for a promise to stay out of politics.
Sharif's strongholds are in urban areas of Punjab, Pakistan's richest and most populous province which returns nearly half of National Assembly members.
He did not appear hopeful of winning seats in Sindh.
"We've never won a National Assembly seat from Sukkur but I still love the people of Sukkur and Sindh ... they've always supported the democratic forces," he told the crowd.
