The government introduced the Fourth Amendment Bill 1968 in parallel, which would have replaced the electoral system for elections to the Dáil from proportional representation by means of the single transferable vote with the first-past-the-post voting system (FPTP) based on single-seat constituencies. A proposed constitutional amendment to introduce FPTP had been proposed by a previous Fianna Fáil government in 1959, and had been rejected in a referendum by 51.8% to 48.2%. The opposition parties Fine Gael and Labour Party presented the two bills in 1968 as a combined attempt by Fianna Fáil to rig the electoral system in its favour.