The Progressive Democrats are "deeply disturbed" by the action of the Minister for Justice in giving temporary release to the four men convicted in connection with the killing of Det Garda Jerry McCabe in Limerick in 1996.

In a highly critical speech, the party's former leader, Mr Dessie O'Malley, said it looked to the PDs like a "gradual build-up to their eventual, premature, total release".

The Limerick East TD said: "When moderate democrats who seek to abide by and uphold the rule of law come a bad second in Government esteem to these kind of people it is surely time to ask ourselves some fundamental questions about how we order our affairs."

The PD Minister of State, Ms Liz O'Donnell, sat beside Mr O'Malley as he raised the issue in a motion on the adjournment of the Dail.

Each release appeared to be based on the "alleged illness" of a family member, he said. "To say the least, the reasons for their release are very dubious and almost certainly would not be adequate if these people were not members of the IRA and did not have the other part of the IRA, Sinn Fein, lobbying for them."

The Minister of State for Justice, Ms Mary Wallace, responded that the High Court had found it would be unlawful for a minister to impose a blanket ban on releases for a particular group of prisoners. Each case had to be considered individually by the Minister.

She fully appreciated the concerns expressed about the releases and nobody could deny the prisoners involved were "party to a dreadful and brutal crime in Adare which shocked all right-thinking people".

Mr O'Malley said that a "freelance, unattached murderer of a garda" would not get this treatment, and questioned why they were not at Portlaoise prison.

Instead, they were enjoying themselves in Castlerea, "in an individual bungalow of their own with telephones paid for by the taxpayer and the IRA, sending down the town for Chinese or other takeaways when ever the normal diet is not to their liking".

Their releases were described in some quarters as "confidence-building measures", he said. "I would have thought that we need to build confidence in the legal system and in particular the criminal-justice system, and not confidence among the members of an organisation that has spent several decades murdering, maiming and robbing people on this island."