The 39-acre Cwmbran former police training college is already owned by the Ministry of Justice, and is located within their original search area of the M4 corridor.

The ministry describes it as a “very good site”, saying it provides good access to the courts and the main centres of population and good road and rail links from Newport and Cardiff.

Covering 39 acres, the ministry adds it would be large enough for a prison of 1500 places.

The South Wales Argus yesterday asked the Ministry of Justice to clarify what category of offenders would be housed at the prison, and how many jobs were likely to be brought to the area if the prison was built in Cwmbran.

A spokeswoman for the Ministry of Justice said: “We cannot speculate about who will be in the prison or how many jobs will be created, as these are only proposals at this stage.”

Sites in Merthyr Tydfil, Wrexham and Caernarfon, North Wales, were also shortlisted. A consultation on the plans is open now until October 31.

Torfaen council leader, Bob Wellington, has called for a large effort from the community against the proposals.

It was agreed at the meeting that the Greenmeadow and St Dials Residents Association will lead a petition against the prison.

Anyone wishing to sign it should call Tom Matthews on 01633 771463.