The Welsh Conservatives’ said any proposal for a new national park “must work with, not against, the people who live and work in these communities”.
Additional bureaucracy could make life harder for the area’s farmers, and “there is also a potential impact on house prices, local infrastructure and tourism pressures, particularly in areas that are already struggling to cope”, the party added.
Plaid Cymru said “there are so many unanswered questions that it’s no surprise that not a single local authority has supported the proposal”.
It continued: “Wales’ existing national parks have suffered years of funding cuts. Surely the priority should be to properly fund those before stretching scant resources even further?”
The Welsh Liberal Democrats said: “Plans for Glyndwr National Park are ill-conceived and being pushed through against clear local opposition.
It would heap more red tape, higher costs and planning barriers onto rural communities that are already under pressure. Instead of helping local areas grow, it risks holding them back and it should be scrapped.”
Reform and Wales Green Party have been asked to comment.