The Health Service Executive (HSE) is facing having to create up to 150 new clerical and administrative posts in the west to replace positions hit by a controversial Government recruitment embargo in 2002.
The move follows a ruling by the Labour Court that the HSE's practice of employing clerical staff provided by an outside agency, on an ongoing basis, breached the terms of national agreements.
The HSE had argued that it had engaged the agency personnel following the introduction of the public sector recruitment embargo in 2002.
In a binding ruling issued on Thursday, the court said that the HSE should restore employment levels for clerical staff in the west to those that existed prior to the introduction of the embargo.
It also found management had breached terms of national agreements by not consulting with trade unions about outsourcing.
In a case brought by the trade union Impact, the Labour Court held that the terms of the national agreements Sustaining Progress and Towards 2016 allowed for such outside staff to be used in emergency situations.
However, it said that the current situation in the HSE-West was "an ongoing issue which needs to be addressed in order to ensure delivery of service".
"The engagement of agency workers in such circumstances diminishes the value of those terms of the agreement," the ruling states.
Impact had sought to have the existing agency staff, who number about 70, converted into direct employees. However, the court recommended that "the normal competition process should be utilised to restore the numbers, and that agency workers should be facilitated to progress their application accordingly".
Impact had argued that by outsourcing clerical work to agency workers rather than employing its own staff at University College Hospital Galway and in primary, community and continuing care services in Mayo and Roscommon, management had breached national agreements.
Management had contended that when the embargo was introduced, it lost the opportunity to fill 150 posts which had been approved and funded at the time.
Management said this meant there was insufficient staff to provide secretarial and support services to newly-appointed consultants. It said to deliver required services, it became necessary to engage clerical and clinical support staff through an agency on an interim basis - and that in those circumstances it was not possible to enter into consultation with the union.
Impact industrial official Denis Rohan said the employment of agency staff was impractical, as the costs were higher than for recruiting permanent HSE staff.
He said agency fees were subject to 21 per cent VAT.
The HSE said the ruling referred specifically to the old western health board area and that it was "a legacy issue from before the creation of the HSE".
"We will be examining the recommendations in the light of the 2007 national employment control framework, and in the context of the funding parameters within which the HSE must work."