A senior US senator urged Pakistani authorities to ensure Monday's elections are free and fair, warning the country could face greater instability if the vote is rigged. "Without an open election that gains the confidence of the vast majority of the middle class here there will be great turmoil," Sen. Joseph Biden, chairman of the Senate Foreign Relations Committee, said in Lahore Sunday. Biden, a Democrat from the US state of Delaware, said a more democratic government would help Pakistan combat spreading Islamic extremism and suggested Washington should reduce its reliance on President Pervez Musharraf. "I do not buy into the argument that the only person who has the capacity to help in dealing with terrorism is Musharraf," Biden said. He also repeated his view expressed to Washington reporters last week that the United States should cut military aid to Pakistan if the election is rigged.