The Communications Minister has suggested it is not legally possible to force media owners to sell their outlets.
It comes after a report, commissioned by Sinn Féin MEP Lynn Boylan, raised concerns about media ownership in Ireland.
The report says too much media is owned by either RTÉ or businessman Denis O'Brien.
It rejects claims that it would be legally impossible to force Mr O'Brien or other owners to sell some of their outlets.
The authors of the report suggest: "There is a school of thought amongst a number of unknown Irish politicians which suggests that no retroactive step could be taken which would alter current media ownership concentration due to the protection of property rights.
"If the protection of property rights is being suggested to be a legal barrier, we are firmly of the view that this is based upon flawed legal analysis [...] In principle, there is no such bar under Irish Constitutional law, the ECHR or EU law."
However, Minister Denis Naughten disagrees.
Speaking to reporters, he argued: "I think what is bizarre about the report [is that] they've dismissed the constitutional issues that we have here in relation to retrospective legislation.
"So I don't know what the logic [is] or how they can dismiss the constitutional challenges," he added.
