Talks are under way today between the Dublin Port Company (DPC) and the Technical Engineering and Electrical Union (TEEU) over a proposed strike at the port.
The Labour Relations Commission invited both parties to talks at its office in Haddington Road.
The TEEU has claimed that five shore staff, who had no training as crew members, were suspended when they refused to man tug boats this week.
Dublin Port Company said the union's claims were "false and grossly misleading" and have come as a "huge shock".
It has denied that any staff were suspended for refusing to operate tugs, although it said some staff had been suspended.
The strike notice expires next Tuesday morning, January 30th, when pickets will be placed on the port.
Seamus McLaughlin, head of operations, Dublin Port Company told ireland.com: "The suspended workers were not asked to work on the tugboats, they were only asked to go out on the vessels as a retraining and familiarisation exercise, which is perfectly in line with the agreement we signed with the TEEU that has been place since last March."
Mr McLaughlin said that the agreement had taken 18 months of talks with the union to achieve and "had cost the company dearly" as some workers received an 18 per cent pay rise. He added that the agreement has eliminated "job demarkation and allows for flexible working".
Mr McLaughlin denied that the DPC had put the men in any danger: "Going out on boats is nothing new, these lads go out on pilot boats every day of the week. I don't believe that the men were put in danger - we are a responsible employer, we would not put our employees in that situation.
"I think this dispute is about certain TEEU members challenging this agreement."
The TEEU rejects the claim by the DPC that shore-based fitters and electricians have only been asked to engage in retraining and familiarisation courses on tug boats moored to the pier.
TEEU Regional Secretary Arthur Hall said this morning: "Our members were ordered to work on board tug boats in Dublin Bay, without training or proper equipment, on the weekend of January 12th to 14th in atrocious weather conditions and the union has statements from members to that effect.
"It was only when the union raised the matter with the company, and with the Health and Safety Authority that the company changed its position and said it would only ask the men to train when the tugs were moored," he said.
"However this is still a major breach of existing terms and conditions. This is the second time within a week that the company has tried to misrepresent what has happened in the course of this dispute.
"Management's priority in this situation appears to be protecting its own stern rather than resolving this dispute through negotiating change with the TEEU," Mr Hall said.
"Nevertheless, the union will be attending the talks at the Labour Relations Commission this afternoon and seeking a solution to the problem before strike action commences on Tuesday," he added.