Patients could be put at risk by new proposals from the European Union, doctors' leaders have warned.
The plans would deregulate services
The British Medical Association has warned against a lowering of doctors' standards in the UK.
The BMA's Dr Edwin Borman said:
"Patients in the UK have different expectations from patients in Germany."
The draft directive - unlikely to come into effect for some two years - aims to create a common internal EU market in various services.
There are also concerns the proposed EU Services Directive could bring an excessively business-oriented approach to healthcare.
It is designed to ensure free movement of doctors and other providers of services around the EU.
The BMA is lobbying for healthcare to be excluded from the measure as it fears the UK would then not be able to ensure doctors are of the highest standard.
It says safeguards must be guaranteed before the plans are approved.
BBC social affairs reporter Jane Dreaper says government ministers support the exclusion of healthcare from the directive.
Dr Borman, head of the BMA's international committee, said the proposals undermined a country's ability to decide what was in the best interests of patients.
"In the UK, clinical guidelines, referral schemes, licence to practice procedures and many other safeguards could all be removed if this directive is adopted," he said.
"Our concerns must be met if patient safety is to be guaranteed and standards assured across the NHS."
Doctors in Germany, France and Poland say they share UK doctors' fears, although the European Commission denies it is trying to tell individual countries how to run their health services.
At present, each EU member state regulates its own healthcare system - setting the standards, clinical guidelines and rules on qualifications for doctors working within its borders.
Under the directive, a member state would have to justify any rules under market requirements, proving them to be "non-discriminatory, necessary or proportional".
In addition, a doctor working in the UK who had qualified in another EU country would effectively be regulated by their home country.
At present, anyone working as a doctor in the UK is regulated by the General Medical Council (GMC).
The GMC said it was studying the directive's implications and working with the commission to ensure safeguards were in place.
Health Minister John Hutton said: "We agree with the BMA.
"We don't believe that the directive should cover health services.
"We are working very hard and lobbying in Europe with other EU member countries, which share our position."
Shadow Health Secretary Andrew Lansley said there was no advantage in moving away from a country-by-country basis because of the differences in services in member states.
"Healthcare services, with the exception of mutual availability to healthcare access in other countries when visiting, should not be harmonised between EU countries," he said.
The BMA plans to raise its concerns with MEPs ahead of a public hearing on the directive in Brussels on 11 November.