Talks at the Labour Relations Commission between management and unions at Guinness are expected to go on late into this evening in an effort to resolve an industrial dispute at the brewery.
A Guinness management spokesman told ireland.comtoday: "The company was still confident of a resolution despite the fact a number of new issues had arisen."
He said: "It is important both sides come to agreement on set of terms."
He confirmed production at the various Guinness sites would cease while pickets were in place. The company could lose up to £15 million a week if the strike persists.
The talks between management and the Guinness Joint Union Forum - representing five of the six Guinness unions - broke down on Tuesday after 10 hours of talks.
The unions - SIPTU, the ATGWU, TEEU, AEEU and UCATT - served strike notice to picket the main production and distribution plants in protest at the proposed closure of a packaging plant in Dundalk, with the loss of almost 150 jobs.
Union officials fear the closure of the Dundalk plant is part of a strategy that will see other plants in the Republic scaled down or closed.
The strike will seriously affect supply and production of Guinness products. Guinness, Smithwicks, Harp, Carlsberg and Budweiser are likely to run out in days.
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