The Fine Gael spokesman on justice, Mr Jim Higgins, has said the drugs problem in prisons is totally out of control.
His comments follow the publication of a Department of Justice report that one in five prisoners first injected illegal drugs while in jail.
Mr Higgins said the Minister for Justice, Mr O'Donoghue, had failed to implement a comprehensive strategy to deal with the appalling drugs crisis in Irish prisons.
He said the Minister should set down a four-year time frame to rid Irish prisons of drugs. This would ensure every prisoner would be put on detoxification from their first day in prison. There should also be a guarantee of follow-up treatment and support, he added.
A Dublin Corporation Sinn Fein councillor, Mr Christy Burke, said Mountjoy Prison was widely recognised as a drugs den which was a threat to the lives of its inmates.
He said Mountjoy should be replaced with a properly equipped institution that would have a drug treatment centre where addicts would have access to counselling and social services.