[2][3] The membership was set by the 2011 Singapore General Election on 7 May 2011 and changed three times due to expulsion of Hougang Single Member Constituency MP in 2012 and resignation of Punggol East Single Member Constituency MP and Speaker of Parliament over extra-marital affairs in 2013, as well as the death of Lee Kuan Yew, former Prime Minister of Singapore and MP of Tanjong Pagar Group Representation Constituency.

The 12th Parliament was controlled by a People's Action Party majority, led by Prime Minister Lee Hsien Loong and members of the cabinet, which assumed power on 7 May 2011.

The Opposition was led by the Secretary General of the Worker's Party of Singapore, Mr Low Thia Khiang.

The Speaker of the Parliament of Singapore was Halimah Yacob, of the People's Action Party.

The NCMP Seats were held by Gerald Giam Yean Song and Yee Jenn Jong of the Workers' Party and Lina Chiam of Singapore People's Party.