Building a metro station at St Stephen's Green would amount to the partial demolition of the national monument.
That's according to the OPW, which has raised concerns about the impact of the MetroLink project on the park.
The OPW has made 28 submissions about state owned properties, such as the GPO and Leinster House, that could be affected during construction of the 18km line from Swords to the city centre.
It told the oral hearing on the project that agreement had been reached on 27 properties but not in relation to St Stephen's Green, which it says it does not accept there will be no demolition or destruction.
The state body has raised concerns about the relocation of monuments in the historic park and the removal of more than 60 trees according to the Irish Times.
Transport Infrastructure Ireland says its conscious of the historical significance of St Stephen's Green and says it's committed to making every effort to mitigate the impacts on the park.
