The Heath Service Executive is expected to provide more details next week on its plans for operating the former Mount Carmel private hospital in Dublin, which it bought last year.
The HSE intends to use the premises in Churchtown, south Dublin, as a community and step-down facility for patients who have completed treatment in acute hospitals.
However, trade unions are opposed to HSE plans to outsource the running of the facility to a private operator.
Siptu set out its concerns about the outsourcing plan at a meeting of the group overseeing the implementation of the Haddington Road agreement in the health sector.
The HSE is expected to report back to the group next Tuesday on the issue.
The HSE intends to convert Mount Carmel to provide 65 short-stay beds which would open on a phased basis from next month. A service provider is to be contracted to provide these facilities on behalf of the HSE.
But Siptu has said it will “confront this decision” and industrial action could not be ruled out.