Facebook parent company Meta and video sharing platform TikTok have both declined invitations to appear before the Oireachtas Media Committee next week.
Twitter was also invited and did not respond.
The social media companies had been asked to appear before the committee on 19 April to discuss future business model plans and their long-term visions for the media sector following the publication of the report of the Future of Media Commission.
In a letter to the committee, Susan Moss, TikTok's Head of Public Policy and Government Relations, wrote that as TikTok did not make a submission to the public consultation on the Future of Media Commission it was respectfully declining the invitation to appear.
"TikTok endeavours to be open about our approach to building trust and safety among our Irish and global community and we would welcome a future opportunity to engage with the Committee on TikTok's approach to data governance and our Trust & Safety operations here in Ireland," Ms Moss wrote.
In an email to the committee, Dualta Ó Broin, Head of Public Policy at Meta Ireland, wrote that there is little that Meta would be in a position to share beyond what the committee would already be aware of.
"As a result, having considered the request carefully, I can't see the benefit to either side of Meta attending this proposed session," Mr Ó Broin wrote.
"Meta welcomes the opportunity to engage with the Joint Committee, and would be happy to do so where the subject or focus of the proposed discussion is clear and where the Committee is engaging with all relevant stakeholders within the internet ecosystem," he added.
