TDs and Senators are to question Dutch experts who recently gave Energy Minister Eamon Ryan a major report comparing overhead electricity pylons and high-voltage power lines with underground cables.
The Ecofys consultants' study followed strong pressure from TDs and Senators across party lines, as well as a major grassroots campaign in the North East, where EirGrid proposes to build a 110km-long ultra high power line across counties Monaghan, Cavan and Meath.
Next Tuesday, members of the Joint Committee of TDs and Senators dealing with energy policy will quiz the experts at a special session in Leinster House.
Anti-pylon campaigners in the North East claim that the experts' report has endorsed the main arguments they have been fighting on.
They have also pledged to keep up their fight to force the lines underground.