The population of the midlands is expected to increase by just over 500 in the next couple of years with the opening of the Republic's newest prison in Port Laoise.
The facility is already being prepared for the influx of prisoners with the arrival of 30 detainees or "trusties", who have moved in over the last fortnight.
Located beside the existing prison on the Dublin Road, the new prison will be formally opened later today by the Minister for Justice, Mr O'Donoghue.
Prisoner numbers will gradually increase to a maximum of 515.
When the prison is working at full capacity the prisoners will be guarded by 400 prison officers who are being transferred from Dublin, Cork, Limerick and Castlerea Prisons.
The prison will also contain a high-security unit for 40 prisoners, but according to Mr Sean Alyward, director-general of the Prison Service, it will be some months before the unit is fully commissioned.
The £40 million prison has the most modern security technology available with the inmates constantly monitored by cameras. The traditional lock-and-key system is being replaced by a key-card system which is used in many Irish hotels.
It will have a flushing toilet in every cell, and each prisoner will have his own living space which prison experts say is essential for well-being.
When in full operation, it is expected that the 167 prisoners who are currently housed in the old Portlaoise building will be transferred.
These prisoners are 38 men who are serving sentences or are on remand for political-related activities and 33 who are serving sentences for other serious crimes.
Block D of the old prison, which currently houses 62 inmates who carry out prison work, has been approved for a major refurbishment programme.
The opening of the building will take pressure off Mountjoy Prison in Dublin which is seriously overcrowded.