General elections were held in Singapore on 7 May 2011. President S. R. Nathan dissolved parliament on 19 April 2011 on the advice of Prime Minister Lee Hsien Loong. Voting is mandatory in Singapore and is based on the first-past-the-post system. Elections are conducted by the Elections Department, which is under the jurisdiction of the Prime Minister's Office. Nomination day was held on 27 April 2011, and for the second election in a row, the PAP did not return to government on nomination day, but it did return to government on polling day. This election also marked the first and the only three-cornered fight since 2001 in Punggol East SMC before it increased to four-cornered fight on a by-election held two years later.