The number of agency nurses assigned to satellite addiction centres across the Dublin Mid-Leinster region is to be halved from today.

The Psychiatric Nurses Association has warned that the cut, ordered by the Health Service Executive, will result in the removal of a vital service for patients who will suffer as a result.

The HSE said users attending the centres will not be compromised clinically by the change.

The non-dispensing satellite centres were set up 12 years ago as "one-stop shops" to support people suffering from addiction problems.