Minister for the Environment John Gormley has used his powers under the National Monuments Acts to make a temporary preservation order for Rath Lugh, a prehistoric promontory fort associated with Tara alongside the route of the M3 motorway.
Opponents of the controversial road scheme had claimed last January that the tree-covered site - a designated monument - was being "directly impacted" by preliminary levelling works carried out by the motorway contractors, SIAC-Ferrovial.
"They were cutting further and further into it," according to Dr Muireann Ní Bhrolcháin, of the Campaign to Save Tara. "Originally, the NRA [ National Roads Authority] said the road was going to be 100 metres away from it, now it's 20 metres."
The Minister asked NUI Galway archaeologist and Tara expert Dr Conor Newman to examine the site and it was on his recommendation that the preservation order was made "to be absolutely sure that the monument is protected", Mr Gormley said.
In making the temporary order, which could become permanent, he said he was "acting in the best interests of heritage and also erring on the side of caution. It was not a 'U-turn', as some have claimed, but consistent with my approach since taking office."
Vincent Salafia, of Tara Watch, said yesterday the order to protect Rath Lugh "indicates a major shift in policy by the Minister, who has claimed that no sites are being improperly interfered with, and that he has not power to act" in relation to the M3.
According to the NRA, Rath Lugh is not being impacted by the motorway, which "skirts the base of the elevated promontory on which Rath Lugh is located, approximately 20 metres below, and will not interfere with the site itself or the view of this site from Tara".
Dr Ní Bhrolcháin noted that Rath Lugh is owned by Coillte Teoranta, the State forestry company. "It was up to them to intervene at the planning stage, but they didn't. At that stage, however, the motorway was to be constructed 100 metres away from the site."
Welcoming the Minister's action, she said it showed that the claims made by those opposed to the route were correct.