It has announced revisions to 10 services from 25 June, with some being rerouted, affecting Coedpoeth, Penycae, Rhostyllen, Llay and other areas.
Local MP Susan Elan Jones and AM Ken Skates have written to Arriva and are calling on Wrexham council to step in.
Arriva has been asked to comment.
Mr Skates said: "In Penycae, these changes will see key areas such as the Afoneitha estate hugely affected, and people fear they will be completely cut off.
"Arriva has stated that long-running parking issues hindering access to the estate have contributed to its decision, so I would implore Wrexham council to act as a matter of urgency."
Wrexham councillor David A Bithell, lead member for environment and transport, said: "These are commercial decisions taken by Arriva and the council unfortunately has no power to prevent them going ahead."
Politicians are calling for bus company Arriva to rethink planned service changes in Wrexham, claiming they act as a "lifeline" for some communities.