State of Singapore. For the first time, Singapore had a fully elected Legislative Assembly. At the 1959 general election held on 30 May that year to give effect to the new constitution, the People's Action Party (PAP) led by Lee Kuan Yew swept into power with 43 out of 51 seats in the Assembly. Since then, the PAP has retained power and formed the Government through successive elections, and Singapore's merger with Malaysia in 1963 and full independence in 1965. In the 1968 general election, the PAP was returned unopposed in all except seven of the 58 constituencies, and won the remaining seats with 84% of the popular vote. Thereafter, every seat in Parliament was held by a PAP MP until Joshua Benjamin Jeyaretnam of the Workers' Party of Singapore won a 1981 by-election in the Anson constituency. Jeyaretnam retained his seat at the following general election in 1984, at which Chiam See Tong of the Singapore Democratic Party was also elected as representative of Potong Pasir. Between 1984 and 2011, the number of elected parliamentary seats held by opposition parties fluctuated between one (after the 1988 election) and four (1991 election). The latest general election in 2020 saw PAP's overall vote share dropped to 61.24% which was the lowest share since the 2011 elections and winning 83 out of 93 seats. For the first time, an opposition party – the Workers' Party – captured multiple GRCs with the newly formed four-seat Sengkang GRC (also the first time a newly formed constituency was won by the opposition on the first attempt) as well as retaining Hougang SMC and a five-seat Aljunied GRC, leaving the PAP with 83 out of 93 seats. By-elections By-elections are elections held to fill seats in Parliament that fall vacant in between general elections, known as casual vacancies. In the past, the Government took the position that the Prime Minister had discretion whether or not a by-election should be called to fill a casual vacancy in an SMC, and could leave a parliamentary seat unfilled until the next general election. However, in the case of Vellama d/o Marie Muthu v. Attorney-General (2013), which arose from a vacancy in Hougang SMC, the Court of Appeal held that the Constitution obliges the Prime Minister to call a by-election unless a general election is going to be held in the near future. However, a by-election need only be called