Water meter installers have claimed that a worker was struck by a van driven by a protester in north Dublin last week.
There were boos in the High Court when lawyers for GMC Sierra read out claims that demonstrators in Cabra blocked emergency services at the scene.
The protesters say they have acted peacefully.
GMC Sierra told the High Court a known protester driving a van on the wrong side of the road knocked down a water meter installer in Cabra last week.
The company said one employee was kneed in the face, while another was followed to a Dart station in a sinister manner
Contempt proceedings against four demonstrators who are alleged to have breached an order providing for a 20-metre exclusion zone around the works will be heard on Monday.
Lawyers for the demonstrators wanted a longer adjournment to legally challenge a finding that while they may face jail they are not entitled to legal aid.
Their solicitor Cahir O'Higgins said: "The stakes are extraordinarily high. They're going to lose their liberty if the court finds against them. That's an extraordinarily profound, difficult and solemn situation for them to be in."
Mr Justice Paul Gilligan's decision not to give the protesters more time was influenced by the four's refusal not to give undertakings to comply with the terms of orders stopping interference with meter installations.