Singapore is a parliamentary representative democratic republic whereby the president of Singapore is the head of state, the prime minister of Singapore is the head of government, and of a multi-party system. Executive power is exercised by the Cabinet from the parliament, and to a lesser extent, the president. Cabinet has the general direction and control of the government and is accountable to Parliament. There are three separate branches of government: the legislature, executive and judiciary abiding by the Westminster system. Singapore has been described as being a de facto one-party state. Legislative power is vested in both the government and the Parliament of Singapore. The legislature is the parliament, which consists of the president as its head and a single chamber whose members are elected by popular vote. The role of the president as the head of state has been, historically, largely ceremonial although the constitution was amended in 1991 to give the president some veto powers in a few key decisions such as the use of the national reserves and the appointment of key judiciary, Civil Service and Singapore Armed Forces posts. They also exercise powers over civil service appointments and national security matters. Political background Singaporean politics have been dominated by the People's Action Party (PAP) since the 1959 general election when Lee Kuan Yew became Singapore's first prime minister (Singapore was then a self-governing state within the British Empire). The PAP has been the only ruling party to form the government since then. Singapore joined the Federation of Malaysia in 1963 and gained independence in 1965 after being expelled. Singapore has consistently been rated as the least-corrupt country in Asia and amongst the top ten cleanest in the world by Transparency International. The World Bank's governance indicators have also rated Singapore highly on rule of law, control of corruption and government effectiveness. However, it is widely perceived that some aspects of the political process, civil liberties, and political and human rights are lacking. Freedom House deemed the press "not free" in 2015. Political climate Domination of the ruling party The Workers' Party (WP) is the leading opposition party. WP took 10 of the 93 parliamentary seats in the 2020 election, while the PAP won the other 83. Another new opposition party, the Progress Singapore Party (PSP), obtained two NCMP seats in the 2020 election. One commonly cited reason for a lack of opposition in Singapore is