A detention centre specifically for people facing deportation may be considered, after it emerged the Garda National Immigration Bureau (GNIB) is leaving detainees at overcrowded prisons without prior consultation.

Gary Gannon, the Social Democrats’ justice spokesman, described the bureau’s actions as “extraordinary”.

He highlighted prison overcrowding at Mountjoy women’s prison, the Dóchas Centre, which was operating at 153 per cent capacity last week.

Minister for Justice Jim O’Callaghan confirmed there were 223 women in custody in Mountjoy at the time, 29 of whom were on mattresses. The centre’s bed capacity is 146.

Expressing concern at the overcrowding, the Minister said there are plans to build another 65 spaces across the prison system in 2026, 26 of which will be new spaces for the Dóchas Centre. This, he confirmed, would increase capacity to 172.

O’Callaghan did not believe “prisons are the solution to all of the ills of society”, instead saying a “combined approach” was needed. He said the Probation Service would this year provide over €21 million in funding to 60 community organisations to cover the costs of providing services and programmes.

He stressed “an awful lot of work” was being done to “facilitate women in availing of supervised temporary release”.

The Irish Prison Service is running a pilot project in Limerick women’s prison to support the needs of women who are transitioning from prison to the community. More than 50 women have accessed the scheme to date, “with approximately 25 successful completions”.

Raising the issue of prisoner numbers in the Dáil last week, Gannon said the GNIB “is showing up at overcrowded prisons to place people into them without any consultation with the prison guards”.

The Dublin Central TD said: “That is extraordinary and it is happening on the Minister’s watch.”

An extra 26 spaces for the Dóchas Centre “will not fix this”, he said, adding: “We need something far more radical and different.”

The Minister told him he recognised the pressures the deportations issue put on the prison system. “Perhaps we need a separate place where people who are going to be subject to enforced deportation can be detained. That is something I will look at.”

The Social Democrats spokesman referenced “jaw-dropping” comments by the Inspector of Prisons, who recently told the Justice Committee conditions in the prison system were “tantamount to torture”.

Recidivism rates in Ireland are nearly seven out of 10. Asking if it was “time to be more radical”, Gannon called for a “full exploration of the prison system” and suggested a citizens’ assembly on prisons and incarceration.

Irish prison conditions among the worst ‘anywhere’, chief inspector tells politiciansOpens in new window ]

He asked: “Do we really need to imprison women whose children will have to visit them and be traumatised by that prospect?”

The Minister rejected the suggestion prison conditions were “tantamount to torture”. He said there was a “a lot of excellent work going on in prisons and a lot of people who come out of prison do not go on to offend again”, adding: “That is particularly the case in respect of serious offences.”

The Minister said he was well aware of people in prison who “because of addiction issues or chaotic lives, do go on to commit further offences”, which was a challenge to deal with.

There are about 5,800 people in prison from a population of 5.5 million, he said.

“We are not a society that is at the higher echelons of incarceration in Europe or in the world.

“We have a moderate view in terms of who needs to be incarcerated,” but “justice sometimes requires incarceration”.