Dr Jane Lothian, secretary of Northumberland LMC, said that the requirement to draw up service lists would create unnecessary work and bureaucracy for GPs. 'The pre-emptive drawing up of lists would be a nightmare.
'It would be almost impossible to draw up a full list of all services. All basic services are available, full stop,' she said.
From 2013, an EU directive will allow NHS patients to receive healthcare from another EU country.
The service received must be equivalent to a service that is provided under the NHS and the patient must consult with their GP before they travel abroad.
In a briefing on the directive, the NHS Confederation said that lists of available services would be crucial.
Such lists would avoid uncertainty and reduce the risk of legal challenges from patients trying to access treatments abroad that are not routinely available on the NHS, the confederation said.
'A key issue with the implementation of the EU rules will be to ensure that commissioners have a clear "list" of which types of healthcare they allow (or do not allow) their patients to receive,' it said.
Elisabetta Zanon, director of the confederation's European office, said that regional variations in service availability meant it was likely the lists would be compiled by local commissioners.