Aer Lingus has said that its ongoing review of ground handling operations in Cork and Shannon have now been extended to include Dublin Airport.
The airline told the union SIPTU, in a letter seen by RTÉ News, that the review will cover all areas of the Dublin operation, beginning with lounge facilities, provisioning stores, fuel and load planning.
It also warned that depending on the outcome of the review, changes could be made to resourcing.
"In the event that following the review, that some areas remain in house, consideration will be given to the grading structures and promotional practices of those areas," the airline's Executive Director of HR and Dublin Airport Operations, Séan Murphy wrote.
Mr Murphy also reminded the union, which represents around 1,100 ground handling staff at the airline, that those who remain in-house will not receive pay increases until 2025 at the earliest.
He said a further series of changes including the allocation of annual leave, the treatment of public holiday benefits and the withdrawal from specific "restrictive" work practices will be finalised shortly.
It followed a similar decision last week by cabin crew at the airline who are members of the Forsa union.
In response, Aer Lingus told cabin managers that a number of staff would be temporarily laid-off and that pay cuts would not be partially restored, as had been hoped following the ballot result.
Since then, however, the company has told Fórsa it will be willing to attend the Workplace Relations Commission in an effort to resolve the issues.
Today’s letter to SIPTU was the airline’s first response to the union since its members rejected the cost-reduction plan.
In a statement this evening, Aer Lingus reiterated that its proposals were the result of many months of engagement and consultation.
"The effects of the pandemic have been prolonged and are ongoing and the requirement for immediate and structural change is urgent," it said.
"Aer Lingus has begun the process of communicating to SIPTU the measures that the airline will now implement in order to deal with the challenges."
Aer Lingus recorded a total loss for the first six months of this year of €199 million, following on from a €361m loss in 2020.