The destruction of the Tara-Skryne valley was "cultural vandalism akin to ripping a knife through a Rembrandt", the Dáil was told during a bitter debate about the M3 motorway.
Labour TD Mr Emmet Stagg (Kildare North) said it was a fact that the road "will destroy the most valuable archaeological, literary and historical site in the country, revered all over the world".
Quoting Irish emigrants who expressed their "horror and disbelief" on an electronic petition organised by the Save the Tara- Skryne Valley Group, one asked: "Are you really going to send millions of tyres over the graves of the high kings?"
He described the Hill of Tara as "as much a symbol of our national identity as the Tricolour.
"It dates back 6,000 years and during most of that period it has been used as the major sacred site in the country."
Mr Stagg called on the Taoiseach to "declare himself as a man of cultural understanding who has the courage to be the 'Taoiseach' in the real sense of the word - the leader or chief who defends Tara from its latest invaders". But the Minister for communications, Mr Dempsey, a TD for Meath, questioned the Labour Party's motives and said they would delay the motorway indefinitely. The road was necessary and would go ahead.
He claimed the Labour Party was trying to get the Government to do what Labour wanted, or they or their associates would drag them through every court in the land. He was speaking on the second night of the debate about the M3 motorway through the Tara-Skryne Valley.
The Labour Party, in a Private Members' motion, called for the Government to discontinue the plans for the M3 route.