GJW Wales' four other staff and its freelancers are understood to have severed ties with the firm.
James is nevertheless understood to be planning to start another agency, called MJ Associates, with Giles Clarke, chair of Swansea-based Pure Water and IT company ATL Telecom.
GJW Wales founder employee Daran Hill told PRWeek: 'I and other members of staff have made the decision not to be associated with any successor businesses that Mari James tries to establish. The PA market in Cardiff is expanding and vibrant, despite some little local difficulties.'
Hill added that he was setting up his own PA venture, Positif Politics.
It has also emerged that the Association of Professional Political Consultants suspended GJW Wales more than a year ago after it failed to update details of its clients and staff.
The Welsh Assembly has this year abolished a number of quangos in a bid to cut bureaucracy and simplify decision making. Most quangos in Wales have retained outside lobbyists.
James did not return calls.