He's suggested four alternative sites, one elsewhere in the Port Talbot area, another near Swansea, one in Pembrokeshire and one in Powys.
Mr Jones says that until now he's not expressed a view because the council will have to consider the planning application. But he is now responding to the prison minister's remarks at Westminster this week, which he feels implied that the council backed the project.
Cllr Jones has followed that up with an angry letter to the Prime Minister, complaining about what the Prisons Minister had said.