The author of the plan to charge a $6 fee for GP visits says hospitals may have to charge a similar fee to stop patients from clogging up emergency departments.

Terry Barnes, the author of a controversial submission advocating the end to free doctor visits for bulk-billing patients, said a similar fee should apply to emergency departments to stop patients abandoning GP services.

''To keep access fair and equitable, but also to ensure that resources are managed properly, the states could charge a matching co-payment for GP-type services in emergency departments,'' Mr Barnes, a former health adviser to Tony Abbott, told Fairfax Media.

In a submission to the federal government, Mr Barnes wrote that it could save $750 million by forcing patients who are presently bulk-billed to pay $6 to visit their GP.

Tracy Schrader, of the Doctors' Reform Society, said if emergency departments started charging patients a fee then it would mean the ''destruction of free point-of-service care''.