The Human Dignity Alliance was born out of a political grouping within Leinster House that met annually. The party was established on 29 June2018 in support of Mullen's pro-life position and was registered with the clerk of Dáil Éireann, to contest Dáil, European and local elections. Mullen predicted the party would be a "slow burner" and see growth over time. In July 2018, independent TD Mattie McGrath ruled out joining the Human Dignity Alliance.