Mullen is first elected to Seanad Éireann (the Irish Senate) in 2007 for the National University of Ireland constituency, and has been continuously re-elected in 2011, 2016, 2020, and 2025, often topping the poll among NUI graduates. In 2018, he founds the Human Dignity Alliance, an anti-abortion political party. He is also affiliated with the European Christian Political Party (ECPP).
Mullen has built his career around social conservative causes:
Anti-abortion advocacy: He opposes the repeal of the Eighth Amendment and seeks stronger protections for conscientious objection among medical staff.
Opposition to same-sex marriage: He is prominent during the 2015 referendum opposing constitutional changes related to marriage.
Human rights and palliative care: He introduces bills and motions promoting hospice care and the protection of vulnerable adults.
Freedom of conscience and family values: He advocates policies emphasizing parental rights in education, ethical protections, and support for families.
International advocacy: He criticizes human rights abuses in China, the treatment of religious minorities, and European Union (EU) bureaucratic overreach, while seeking Ireland’s engagement on human dignity standards internationally.
A lifelong practicing Roman Catholic, Mullen emphasizes the principle of human dignity in both politics and daily life, integrating faith and reason in his ethical framework. He maintains a connection to Irish culture and the Irish language, and has engaged in public discussions on moral and social issues, grounding his positions in Catholic teaching without seeking to impose religious law.
In summary, Mullen is a long-standing independent Irish senator influential in debates on social policy, ethics, and human rights. His career is marked by consistent advocacy for pro-life positions, family integrity, and freedom of conscience, alongside active engagement in European and international policy discussions on human dignity and social justice.
Byrne is Head of Communications with the Higher Education Authority (HEA) until 2019, and has been Vice-President of the National Youth Council of Ireland. In 2014, he is named as one of the European 40 Under 40, in the European Young Leaders Programme.
In January 2006, The Sun includes Byrne’s picture on the cover of its Irish edition beneath the headline “Bertie‘s FF Man in Gay Web Shame,” revealing that Byrne has a profile on the dating website Gaydar. He responds at the time, “I have not, nor have I ever, done anything illegal and I am not a hypocrite in any way. My views on gay rights issues are well known. I am not married with four children or anything like that, so there is no suggestion of hypocrisy.” His family and political career suffer as a result and he is not selected for candidacy in the 2007 Irish general election following this incident. He later describes how a journalist from The Gorey Echo first approaches him, “The first few questions were about roads. Then the journalist said, ‘Are you aware you have a profile on this dating website?'” When he confirms that the profile is his, he experiences a sleepless night before The Gorey Echo outs him locally: “I was ringing around people I knew and my parents were ringing around people … my grandmother didn’t know and a lot of my extended family and my friends didn’t know.” Gorey Echo group editor Tom Mooney defends the publication by saying he believes Byrne’s behaviour to be “unfitting of a public representative.”
Byrne contests the 2019 European Parliament election for Fianna Fail in the South constituency, having unexpectedly beaten Cork TD Billy Kelleher in the vote for the party’s nomination. However, Kelleher is later added to the ticket. Fianna Fáil then divides the constituency geographically, asking people in counties Carlow, Kilkenny, Laois, Offaly, Tipperary, Waterford, Wexford and Wicklow to vote for Byrne, and those in counties Cork, Kerry, Clare and Limerick to vote for Kelleher. Kelleher wins 11.69% of the first-preference votes (FPV) and is elected on the 17th count. Byrne wins 9.62% of the FPV, and is eliminated on the 16th count.
Byrne is elected as a TD at the 2019 Wexford by-election. Andrew Bolger is co-opted to Byrne’s seat on Wexford County Council following his election to the Dáil. His maiden speech is about housing solutions and the need to address the challenges facing Generation Rent. In an interview he says he can envisage a United Ireland where the 12th of July and Saint Patrick’s Day are public holidays and speaks about how Ireland needs to ensure Unionists feel at home in a new agreed state and that may mean addressing issues such as Ireland joining the Commonwealth.
Byrne loses his Dáil seat at the 2020 Irish general election, following what he calls “a dirty campaign.” His defeat after only 71 days makes him the TD with the second-shortest term of service, after the Anti H-Block TD Kieran Doherty, who dies on hunger strike in August 1981, only 52 days after his election.
On March 31, 2020, Byrne is elected to Seanad Éireann at the 2020 Seanad election. He is named as Fianna Fáil spokesperson on Higher Education, Innovation and Science by TaoiseachMicheál Martin in July 2020.
At the 2024 Irish general election, Byrne is elected to the Dáil. He is subsequently appointed Cathaoirleach of the Joint Committee on Artificial Intelligence.
Byrne is openly gay. As of 2020, he is single and describes politics as “almost like an addiction,” which makes relationships difficult. He lives in Gorey.
In March 2025, Byrne is injured during the theft of his phone in London.
