Welsh Secretary David Jones backing North Wales prison
Welsh Secretary David Jones has said he will press the case in the UK government cabinet for a prison in north Wales.
The region is being considered as a possible location for a new "super" prison capable of holding more than 2,000 inmates.
London and north-west England are also in the running.
Justice Secretary Chris Grayling also announced plans for extra accommodation at HMP Parc Prison in Bridgend.
Clwyd West MP Mr Jones said he had discussed a prison in north Wales with ministers and local council leaders.
He said: "I will continue to press the case with the justice secretary.
"A prison in north Wales would create economic opportunities and secure new jobs.
"I also know how important having a prison in north Wales would be to families and professional advisors of prisoners."
Politicians from other parties also backed the idea.
There is currently no prison in north Wales, prompting concern about the impact on prisoners and their families.
Liberal Democrat AM Aled Roberts said many prisoners from north Wales were locked up a long way from the region, putting a strain on their families who have to travel to see them.
He added: "There are significant jobs and economic development gains for north Wales should this project go ahead and we must work on a cross-party basis with our six local authorities, as well as Welsh and UK government ministers, to ensure that our region is properly considered."
Plaid Cymru MP Elfyn Llwyd said holding prisoners far from their homes hampered their rehabilitation.
He said: "This link is severed when Welsh prisoners, and particularly Welsh speaking prisoners, are held in institutions hundreds of miles from home and their connections."
However, he said a prison with a capacity of 2,000 prisoners would be too big for the area and that an institution with capacity for 650-750 inmates would be more appropriate.
Politicians in mid Wales reacted with dismay to news that Shrewsbury prison is to close - one of seven in England that are shutting. Six are to close altogether while the Ministry of Justice says a prison on the Isle of Wight will be partially closed.
Mid and west Wales Lib Dem AM William Powell said he was "devastated to hear that Shrewsbury prison is to close".
"I know at first hand the governor's commitment to restorative justice," he said on Twitter.
Montgomeryshire Conservative MP Glyn Davies said: "The closure will have a very negative impact on mid Wales as well as Shropshire.
"One of the biggest challenges that prisons face is to ensure prisoners do not lose contact with their home communities, particularly as this community contact reduces re-offending.
"I desperately hope the innovation and successful rehabilitation achievements seen at Shrewsbury prison can be transferred to the other prisons to which local prisoners will be transferred - including any new super prison that will be built."
Shadow Welsh secretary Owen Smith said: "I welcome the possibility that north Wales could be the location for a new super prison somewhere down the line but the more immediate and definite news today is the closure of another six prisons with a total loss of 2,600 prison places over the next three months."
He said people in Wales needed assurances from the UK government that there was enough capacity in the prison system for people convicted of serious crimes.