The Constitution of the Irish Free State, adopted on independence in 1922, prescribed proportional representation for elections to Dáil Éireann.

Under the Constitution of Ireland adopted in 1937, Article 16.2.5° prescribed PR-STV, while 16.2.6° specified that the number of members in a constituency would not be less than three.

An amendment to the 1937 constitution must be proposed as a bill initiated in the Dáil and be passed or deemed to have been passed in both the Dáil and the Seanad, before being submitted to a referendum in which all Irish citizens on the electoral register are eligible to vote.

The amendment proposed to alter the electoral system for elections to Dáil Éireann to first-past-the-post (FPTP) under single-seat constituencies.

It also proposed to establish an independent commission for the drawing of constituency boundaries on a constitutional basis.