New jail will make an annual saving of over €20,000 for each prisoner

I REFER to the column by Fergus Finlay (Irish Examiner, July 4) concerning the estimated cost of running the proposed new prison development to replace the Mountjoy prison campus at Thornton in north Co Dublin.

Mr Finlay bases his column on the presupposition that the cost of running the new prison development can be calculated by taking the average cost of keeping a prisoner in custody (€83,500 in 2004) and multiplying it by the total capacity of the new prison campus.

On this basis, he reaches the conclusion that the new prison will cost €100 million a year, or a billion euro a decade to run.