The construction sector is facing industrial disruption as crane drivers belonging to Unite prepare for a strike that could seriously hit activity on building sites around the country from next week.
Unite says it represents 90% (around 170) of the country's crane drivers, though that figure is disputed by SIPTU, which has traditionally represented the grade.
The union is pursuing a 10% pay claim for the crane drivers that would bring their hourly rate to around €24.
The union has already balloted crane drivers working on sites belonging to seven firms which do not belong to the Construction Industry Federation, and which the union claims have refused to engage with them on their grievances.
Those intermittent rolling strikes will hit a number of sites from 27 June.
However, the CIF has now withdrawn from its negotiations with Unite on the basis that the union is engaged in industrial action.
Unite has now pledged to ballot members on CIF sites, with nationwide industrial action possible from 13 July.
Unite Official Tom Fitzgerald said a strike by crane drivers would have a massive effect on productivity on sites - particularly as other construction workers would probably refuse to pass the Unite picket.
The CIF confirmed that Unite had served notice of industrial action, adding that it continued to request that all issues be dealt with through established processes and protocols.
A construction industry source acknowledged that any such stoppage of crane drivers could have massive consequences on numerous sites with implications for a number of key projects.
Last month, SIPTU signed an agreement with the CIF that would give crane drivers up to two hours' extra pay per day for "greasing" time to lubricate crane cables at the beginning and the end of the day.
SIPTU has complained to the ICTU about Unite's recruitment of crane drivers.
Meanwhile the CIF and unions are due to attend the Labour Court on Monday to hear an application for the establishment of a Sectoral Employment Order which would set down a legally binding pay framework for the construction sector.