Minister for Justice Michael McDowell is expected to come in for intense questioning next week in the Dáil over proposals for a new prison in north Co Dublin.
Labour TD Joe Costello indicated the Opposition parties will present a cross-party motion concerning the Minister's approval of the acquisition of lands for the proposed new prison in the Kilsallaghan townland in north Dublin.
"The fact that this matter is going to be first on the agenda is indicative of the priority that we [ Opposition parties] are giving it," Mr Costello said.
The motion will seek an examination of the process that led to the selection of Thornton Hall as a prison site.
Criticism has been voiced at the recommendation to pay almost €30 million for 150 acres of unserviced agricultural land, a figure allegedly between six and eight times what it would be worth on the open market.
Agreed in January, the deal is due to be completed early next month when the outstanding 90 per cent of the purchase price is to be paid by the State.
The absence of an appropriate Environmental Impact Statement has already led to the matter being referred to Europe.
Mr Costello was speaking at the publication of The History and Archaeology of the Parish of Kilsallaghan, by Dr Mark Clinton, who directed excavations at Carrickmines. The prison site is in the parish.
The book, commissioned by the Kilsallaghan Residents' Heritage Association, indicates there are up to 33 known sites or sites of potential archaeological interest - some of which may date from the Neolithic period - on the land surrounding the site.
Resident Richard Merne applied to the High Court this week for leave to access the lands for archaeological assessment. The court indicated it will hear the matter next week.
Earlier this year Mr McDowell said the site had been inspected for archaeological features "and none were found", adding he would not be put off from building a prison by any "guff about fairy forts or architecture".
However, yesterday it emerged that in 2000, when the National Roads Authority was assessing route options for the M2, their consultants ruled out building in this area.
They advised a route farther west, noting the Kilsallaghan district was a "high-quality traditional farm landscape with mature and ancient hedgerow features".