The Campaign to Save Tara is to distribute about 100,000 flyers in advance of the general election with the aim of making the M3 motorway a "make or break" issue for parties who would form the next government.
Outlining the campaign's election strategy in Dublin yesterday, its spokesman Michael Canney, said it was asking people to "consider each candidate's and party's position on the route to the ballot box".
"We will encourage people to vote for the candidates who provide written commitments that they will support a review of the route [ through the Gabhra Valley, east of the Hill of Tara] if they are elected to government".
It was not "just another road through a scenic place, but something that will alter an entire archaeological landscape".
An independent poll in 2005 found only 25 per cent of those surveyed wanted the M3 to go ahead as planned.
Mr Canney said the campaign aimed to "translate the deep unease people feel about this issue into a positive outcome in the election", adding that the "anti-Tara parties - Fianna Fáil, Fine Gael and the PDs - will be forced to deal with it on the doorsteps".
Although the group was pleased with support from the Labour Party, the Green Party and Sinn Féin, he said it was vital these parties maintained their position if they entered into talks to form a government.
Dr Muireann Ní Bhrolcháin, senior lecturer in Celtic studies at NUI Maynooth, said: "If the Gabhra Valley is not safe, nowhere in Ireland is safe from future development in the spurious name of progress."
Architect and broadcaster Duncan Stewart called the M3 "the worst example of unsustainable development" because it would encourage more sprawl.