Sinn Féin has called for the immediate halting of work on a wind turbine near a Neolithic cairn in Co Down pending a public inquiry, after the council in charge of the site said it would no longer be intervening to prevent construction.
Armagh City, Banbridge and Craigavon Borough Council said it would not be extending a 28-day stop notice, which expired on Monday, which had been enforced on work near Knock Iveagh cairn near Rathfriland.
The council introduced the notice as it investigated alleged breaches of planning controls for the turbine concerning the access road and electricity network, but has now said work can continue as the developer has been ordered to make amendments.
Lorries began arriving at the site yesterday morning as construction resumed.
Campaigners believe the cairn, a large stone mound covered by earth which would have been used as an ancient burial chamber, could be historically significant and that work could damage the 6,000 year-old site.
Planning permission was granted in 2013 by the former Department of the Environment.
Sinn Féin said there were "flaws" in the original application process, with local residents and experts from the Historical Environment Division, the body within the Department for Communities (DfC) that protects the north's heritage, not consulted.
Newry and Armagh MLA Cathal Boylan said: "Sinn Féin are calling for all work to be suspended until a full public inquiry can be carried out to establish the full impact of the development."
Campaigners have raised more than £1,400 through crowdfunding with a view to launching a legal challenge.
The Friends of Knock Iveagh, which opposes development near the cairn, said it was "appalled" at the council's decision.
"ABC Council appears to have taken the view that because these unauthorised works have already started, they should be allowed to continue, regardless of how much damage has already been done, or will be done, or of any any flaws in the process for approving the turbine."
In a statement, the council said that requests to revoke planning permission remain "under consideration".
It is understood that councillors have been warned that the council may have to pay compensation to the developer if permission is overturned.