The group, Bantry Bay Native Kelp Forest, will hold the protest in advance of a private members bill due to be brought by Donegal Independent TD Thomas Pringle and Galway West Independent TD Catherine Connolly at 2.45pm.
Last December, it emerged that final approval had been given for the start of the largest kelp harvesting operation in the country, with Tralee-based BioAtlantis saying it hoped to begin harvesting kelp in the area, following a lengthy application process.
The company hopes to extract and purify compounds from kelp which will be used as a substitute for antibiotics in the pig and poultry industry.
The overall area licensed for harvesting of the seaweed is around 1,800 acres, though BioAtlantis said the area to be harvested annually is 25% of this, around 456 acres per annum, of which less than 40% contains kelp.
More than 12,000 people have signed a petition asking for the licence to be rescinded, and protesters will demonstrate at 2pm outside Leinster House before holding a press conference at 2.30pm at nearby Exchequer St.
Those opposed to the Bantry Bay kelp harvesting operation believe insufficient consultation took place and also argued that no Environmental Impact Assessment was conducted.
BioAtlantis has maintained that there has been “a considerable level of misinformation” in relation to its plans and said the area to be harvested annually was just 0.3% of the total marine area of the bay.