The change in the law would result in a competitive distribution system that would, according to the PPA, lead to powerful retailers being able to choose their wholesalers.
The Department of Trade and Industry (DTI) is set to push the legislation through next May.
Publications are currently distributed on an "exclusive territories" basis where wholesalers compete to supply a region of the country. According to the PPA, a change to that arrangement would be a danger because wholesalers would view smaller retailers in rural or socially deprived areas as uneconomic.
"This is a major threat to publishers of smaller magazines, potentially some newspapers and newsagents," said PPA chief executive Ian Locks. "We are currently applying for a block exemption from the legislation that would keep the exclusive territories arrangement."