Trinity College Dublin has expressed "extreme concern" at Rail Procurement Agency (RPA) plans to bore tunnels under some of the college's historic buildings during construction of a metro route.
Proposed east, west and central routes would all require tunnelling under the college campus.
"All three mutes (sic) proposed travel under important historic and priceless buildings. The contents of many of these buildings are also priceless," says a submission from Trinity's director of buildings Paul Mangan to the RPA.
Under current proposals the eastern route would travel underneath the Rubrics, the college's oldest building, which was built circa 1720 and is now used for accommodation. It would also travel under the arts building.
Tunnelling would then continue underneath the Old Library which was built in 1712. According to the submission, this is "one of the city's most historic buildings".
Tunnelling for the central route might not be feasible because of the deep double basements of the recently-constructed Ussher Library. The submission states: "This level is lower than the proposed rail level for the metro at this location. It is obvious that it would be impossible to tunnel under the library given these circumstances."
Work for the western route would require tunnelling under the provost's house. Trinity is concerned this could damage the house's "elaborately decorated" interior which has Rococo plasterwork in its salon and dining rooms.
The submission warns that older buildings' foundations have been complicated by repairs.
"Our primary concern is about the integrity of our historical buildings," said Mr Mangan. "We're concerned about our ability to continue academic activity."
Tunnelling, he said, could damage soil conditions under buildings and have an impact that might not be seen immediately.
He said there were other options available to the RPA such as tunnelling under streets.
A spokesperson for the RPA said: "We've evaluated Trinity's submission and we will take it into consideration when we decide on a route.
"Nothing is impossible when it comes to tunnelling. There would be no physical obstacles and we would be talking about tunnelling 20 metres under Trinity."
The RPA is due to make a decision on the route at the end of next month.