Campaigners battling to re-route the controversial M3 motorway away from the Hill of Tara in Co Meath have served Minister for the Environment Dick Roche with notice of a Supreme Court challenge to the project.
Lawyer Vincent Salafia revealed he was appealing a High Court ruling clearing the way for the divisive road.
But he said with a general election due next year he was still hopeful the Government would try to appease voters by doing a u-turn on the project.
"While the case is proceeding logically to the Supreme Court, and Europe if necessary, we are still hoping for a political decision by the authorities to review the situation and consider re-routing the Tara section of motorway," he said.
"With an election coming up, the Government is acutely aware that 70 per cent of people surveyed nationally in 2005 said they wanted the motorway rerouted away from Tara.
"The M3 actually goes over three kilometres off course to the east, to split the Tara valley, which has few inhabitants. If it went the same distance in the opposite direction it would service Trim and save Tara."
Formal written notice of the Supreme Court action is today being handed to Mr Roche, the Attorney General, Meath County Council and the National Roads Authority.
Mr Salafia lost his High Court challenge to the M3 last May. He claimed the National Monuments Act 2004 is unconstitutional, because it does not pass the test laid out by Miss Justice Mary Laffoy in the M50/Carrickmines Castle case.
In that hearing she recognised the constitutional imperative on the state to protect the national heritage.
The Act, introduced by then minister Martin Cullen, drastically rewrote heritage protection legislation giving the minister sole discretion in deciding whether any archaeological site is a national monument and whether it can be demolished.
Mr Salafia has also claimed the directions given by the minister, for excavation of 38 archaeological sites along the route chosen by Meath County Council and the National Roads Authority, are unconstitutional. They were carefully drawn up to suggest the motorway would help preserve Irish heritage. But Mr Justice Thomas Smyth in the High Court rejected Mr Salafia's claims.
PA