Line of succession to the President of Pakistan: Pakistan, by law, has a parliamentary democratic system of government that has been modified several times since its inception. The prime minister of Pakistan is the head of the government, while the president of Pakistan, by law and by statute, is a constitutional figurehead.
The constitution does not allow a vice president, but the chairman of the Senate of Pakistan officiates in the absence of the President and takes over on the President's death or removal from office. If the chairman of the Senate is not available, the speaker of the National Assembly performs the duties of the president of Pakistan. The Electoral College of Pakistan is responsible for electing a new president. The Amendment XVIII, Article 49 of the Constitution of Pakistan covers this matter.
Chairman or Speaker to act as, or perform functions of, President
In this article, the Chairman refers to the Chairman of the Senate of Pakistan.