Irish MEP Barry Andrews has warned that social media has "become a geopolitical battleground".
The Fianna Fáil MEP said the quality of X has "drastically declined".
"Just in the last week, Elon Musk has made clear he wishes to destroy the European Union and is using his own platform to do so," Mr Andrews said.
"EU regulators and legislators must wake up to this reality."
X has blocked the European Commission from buying ads on the social media platform, days after it fined Elon Musk's site €120 million over its blue tick badges.
The fine was the first issued under the EU's new Digital Services Act and has led to increased tensions between the US government and the EU.
We need your consent to load this rte-player contentWe use rte-player to manage extra content that can set cookies on your device and collect data about your activity. Please review their details and accept them to load the content.Manage Preferences
RTÉ’s This Week asked all 14 MEPs how often they use X and if their opinion of the platform has changed either since the social media platform was purchased by Elon Musk or since X has terminated the European Commission's advertising account last week.
Twelve of the 14 replied. Labour's Aodhán Ó Ríordáin left X in November 2024 as a result of what he saw as the deteriorating state of the platform.
None of the others that responded indicated that they would leave.
'Petty retaliation' by X, says Ó Ríordáin
Mr Ó Ríordáin called the move by X to block the European Commission's advertising account as a "petty retaliation".
"The EU’s fine is about basic consumer protection. It shows we stand up for our people, not the unchecked greed of reckless and childish tech billionaires," he said.
Fianna Fáil's Cynthia Ni Mhurchu said she uses her X account daily.
She told RTÉ's This Week: "Services such as Twitter -or X - play an important role in enabling engagement with constituents on issues relevant to my work."
"Under Elon Musk’s leadership, X has seen weakened content moderation, a surge in misinformation, and a growing number of bots and fake accounts amplifying false narratives," she said.
"The platform has repeatedly disregarded clear obligations established under EU law, including the Digital Services Act."
She added: "Whether I leave the platform or not, is not the question - the real question is how effective the EU will be at enforcing our laws and ensuring that if X wants to operate within the EU, they play by our rules."
Sinn Féin's Kathleen Funchion said that her X account is the social media platform that she uses the least.
She said: "I find X to be a very negative space, full of anonymous accounts and bots."
Fianna Fáil MEP Billy Kelleher has said that while he still uses X, he doesn't use it as much since the platform was purchased by Elon Musk.
"I tweet less and am highly conscious of the number of fake accounts spreading misinformation, disinformation and nakedly populist, extremist content," he said.
Party colleague, Barry Cowen also said he uses X far less than he used to.
"My concerns about Twitter/X and its declining usefulness are not new and go back some time, not solely to recent developments under Elon Musk or the termination of the European Commission’s advertising account.
However, he added: "That said, I still believe that any credible way of reaching people with information about my work and representing their interests should be used, even as the nature and tone of platforms continue to change."
MEPs using X to keep constituents up to date
Fine Gael MEPs Sean Kelly, Nina Carberry, Maria Walsh and Regina Doherty all said that the use X to keep constituents up to date on their work in the European parliament but have noticed an increase in bots on the platform.
Ms Walsh added: "In recent months, I have adjusted my approach to X by tightening my moderation settings. This was due to a marked increase in targeted trolling, and the absence of robust moderation on the platform."
Independent MEP Michael McNamara posts on X several times per week.
"My opinion on the use of X hasn’t changed much since it was purchased by Elon Musk, other than maybe there’s an exchange of bias in political direction from one to another," the Ireland-South MEP said.
"X’s termination of the European Commission's advertising account last week is a matter of indifference to me."
Independent Ireland MEP Ciaran Mullooly said he reviews his usage of his X account on a monthly basis.
Ireland's European Commissioner Michael McGrath has not posted on X since mid-November.
A spokesperson for Mr McGrath said there was no special reason for this.
While Independent MEP Luke Ming Flanagan and Sinn Féin’s Lynn Boylan did not respond to a request for comment, but both have active X accounts.
