Modular homes for homeless families will not be delivered in time for Christmas after threats by masked men to set fire to machinery on one of the sites.
The Government planned to have 22 families, currently living in hotel rooms, housed in the prefab units in Ballymun, Dublin, next week.
In a statement Dublin City Council (DCC), which has been leading the project, outlined how a protest held on the site during the first week of work "escalated".
Some of those protesting peacefully at the site were there to seek a refund they had paid for co-op housing on the same site more than 10 years ago.
But separately, people wearing balaclavas later threatened staff on the night of Thursday November 26, the day the protest began.
Staff from Western Building systems were allegedly told to "go back to the North or their machinery would be burned out".
The intimidation continued the next day, according to DCC.
The contractor reported that those threatening his staff said that "should he attempt to proceed with any works at the site there would be an additional 150 protesters on the site".
He also received threats that this machinery "would be burnt out", the council has revealed.
It was not possible to resume work on site until December 3 due to bad weather in the days after the protest, causing further delays.
The firm offered to have some of the units ready for next week but the council opted against this because they didn't want to leave any unfinished units exposed over the holiday season.
Environment Minister Alan Kelly, who fast-tracked the project, said yesterday he was looking forward to the early delivery of the units in the New Year.
As late as last Saturday, the minister said he was "confident" that some of the units could be delivered.
"I'm confident that a certain volume of the units will be in place before Christmas," he told RTÉ's Marian Finucane.
However, the Labour TD susequently said that some "frankly pretty nasty" protesting had delayed the work.
Meanwhile, homelessness campaigner Fr Peter McVerry said that the delay was a "huge disappointment" for people.
"It's very disappointing. The difference between a hotel bedroom and a modular home is a world apart," he told the Irish Independent.
"It's disappointing for the families who were hoping to move in to a house and especially for the kids.
"Hopefully, they can be in as quickly as possible in the New Year."
The Ballymun development, named Baile Na Loachra, is the first tranche of the 150 fast-tracked units pledged by the Government to tackle the homeless crisis.
The latest figures show that there are 705 families with 1,466 children in emergency homeless accommodation in Dublin.
Four other sites have already been selected across Dublin to accommodate the remainder of the two and three bed units.
A tender process to build these began yesterday.