Protesters vowed on Thursday to press ahead with a major march onto Pakistan's parliament in defiance of bans and hundreds of arrests by a government that has come increasingly under fire from its critics. The country's largest opposition party has joined forces with lawyers demanding an independent judiciary in a protest movement that threatens to weaken the year-old elected government, which the U.S. is counting on to battle Taliban and Al-Qaida militants operating in the tribal areas along the border with Afghanistan. Police rounded up around 300 political activists on Wednesday from cities around the country seeking to cripple the rally before it began. It also banned rallies in two provinces. Media reports the government planned to blockade the capital. "Our long march will go ahead according to the schedule,'' said Naeem Qureshi, a prominent lawyer in Karachi, referring to the protest. He and others lawyers in Karachi were scheduled to leave for the capital Islamabad later Thursday in a motor convoy, where they hope to join thousands of other protesters for a rally at the parliament on Monday. The growing political unrest is raising the specter of a possible military intervention in a nuclear-armed nation prone to army coups. Human Rights Watch urged Pakistan to free those arrested. Pakistan's lawyers are demanding that President Asif Ali Zardari fulfill a pledge to restore judges removed by Musharraf. Opposition leader Nawaz Sharif, supports the judges' restoration but also is furious over a Supreme Court decision barring him and his brother from elected office. After the ruling, the federal government dismissed the Punjab provincial administration led by Mr. Sharif's brother. Mr. Sharif claims the ruling was politically motivated and has urged Pakistanis to join the protest march. Information Minister Sherry Rehman told reporters 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 Musharraf, but a few, including a former Supreme Court chief justice, have not regained their seats.