Fishermen from north and south of the Border have formed an alliance to oppose what they describe as "drastic EU threats" to their livelihoods on the Irish Sea coastline.
Industry representatives from several Irish Sea ports and from Britain agreed to unite at a meeting this weekend near Dundalk, Co Louth.
Mr Lorcan Ó Cinnéide, chief executive of the Irish Fish Producers' Organisation (IFPO), said that fishermen had always co-operated at sea, and it was now time to extend this co-operation on land.
The meeting resolved to resist "unworkable, ill-thought out and simplistic measures proposed by the EU in relation to fishing and other measures".
Mr Ó Cinnéide, who made a detailed presentation to the meeting,said that the atmosphere was very positive, in spite of the diversity of interests.
"It was agreed to work closely together in the political and scientific spheres and to send the message as strongly as possible that while fishermen are more than prepared to participate fully in stock management and conservation, we cannot accept either the current diagnosis or the EU's solution," Mr Ó Cinnéide said.
Irish Sea fleets face an extension of the "days at sea" restrictions, which have already tied up whitefish vessels in the north-west for all but 11 days a month.
The restrictions were introduced by the EU to conserve cod stocks in the North Sea, in spite of pleas for application of technical conservation measures and closed areas.
The Donegal port of Greencastle has been badly hit, as larger boats have moved south and smaller vessels have been unable to put to sea.
The fishing industry representatives established a steering group at the weekend in Co Louth, and its initial priority will be to review in detail the scientific analysis on cod and other stocks.
It will also organise meetings with the respective fisheries ministers in the Republic and Britain.
"This is only the beginning," Mr Ó Cinnéide said after the discussion. "The EU, as well as the governments, can consider themselves put on notice that united Irish Sea fishermen will not be rolled over and put out of business."
Meanwhile, the separate issue of the Irish Box is expected to arise at this month's fisheries council in Luxembourg on June 10th and 11th.
A compromise "box" proposed by the European Commission has been described as insufficient by the Government.