About 100 protesters marched to Government Buildings in Dublin on Saturday to call on Taoiseach Bertie Ahern to intervene and halt work on the M3 motorway through the Hill of Tara.
Organisers of the Love Tara march said that it was an opportunity for people to express their dissatisfaction at the routing of the motorway and would be followed by a "day of action" at Tara tomorrow.
The protest followed the release of a preliminary report from the European Parliament's petitions committee, which criticised the routing of the M3. The document said the committee's delegation was "perplexed by the choice of route and by the damage done to the integrity of the many sites in the Tara area and the Gabhra valley".
An Bord Pleanála ruled last month that the M3 could be built over newly-discovered 2,000- year-old ruins at Lismullen, about 2km from the Hill of Tara. Meanwhile, it was announced that dozens of harpers plan to gather outside Dáil Éireann next Saturday to protest over the planned route of the M3.
Laoise Kelly, of Tara Harpers, said she hoped that more than 100 harpers and harpists would join the musical demonstration. Traditional musicians generally refer to themselves as harpers while classical or pedal musicians prefer the term harpist.
She said that the musicians were taking this action because Tara was the home of the harp. It had been the gathering place for thousands of harpers as far back as 500BC and the harp was a key part of the old Irish parliament.
Ms Kelly said that, to her knowledge, this would be the first time that harpers and harpists had come together to protest over an issue.
"The last time we had to come together as harpists was in 1792, when the tradition of harping was dying out and the Belfast Harp Festival was organised. Only 11 turned up," she said. "But I would hope that we would get up to a 100 or more on Saturday."
The musicians will give a petition to Minister for the Environment John Gormley, calling on him to change the motorway route.
It will say that the continuation of the current plan would be "an intentional and wilful destruction of the home of the national symbol of Ireland".
Three other demonstrations against the motorway route will be held in the United States on Saturday.