He was elected to
Waterford City Council at the
2004 local elections and retained his seat at the
2009 local elections. He became a member of in May 2011, as a senator for the
Labour Panel.
The Irish Times described him in the Seanad as "a frequent, informed and often abrasive contributor across a wide range of areas, with a keen attention to the nuances of legislation". He unsuccessfully contested the
Waterford constituency at the
2002,
2007 and
2011 general elections, before winning a seat in
2016. He was re-elected in
2020, when his 20,596 first preference votes amounted to 1.95
quotas, Cullinane drew criticism on election night when a 30-second video uploaded to Twitter showed him ending his election victory speech with the phrases "up the Republic, Up the
'Ra and ". When questioned about the appropriateness of using these phrases associated with support for the IRA, Cullinane stated: "Yesterday was a very emotional day for me ... It was a long count and obviously we were very excited and very proud of the vote we got yesterday in Waterford. The 30-second clip was part of a longer speech that I gave where I was reflecting back on the
hunger strikes, reflecting back on the fact that
Kevin Lynch stood in the Waterford constituency in 1981. He was someone who inspired me and inspired I think many
republicans. The comments were made in that context." At the
2024 general election, Cullinane was re-elected to the Dáil. In April 2025 Cullinane, 's health spokesperson, was criticised for describing the
British Supreme Court ruling in
For Women Scotland Ltd v The Scottish Ministers (which defined “woman” and “sex” to exclude
transgender women from legal recognition) as a “common sense judgement” worth considering in Ireland. After Cullinane deleted the post and issued an apology, Trans and Intersex Pride Dublin threatened to ban from its July march unless the party clarified its stance and reversed support for a
puberty blocker ban in Northern Ireland. The group accused of enabling anti-trans policies in
Northern Ireland while “
pinkwashing” its image in the Republic. ==References==