Controversial plans to make it much easier for NHS patients to demand free treatment in any EU country were shelved this morning amid a behind-the-scenes row over exactly how an open market in public healthcare should work.

The European Commission wants to enable any patient with a doctor's referral to be able to claim treatment in any of the 27 member states, paid for by the patient's home country.

A spokesman said that the proposed directive in cross-border healthcare was delayed because it coincided with another big decision due to be taken today on proposed CO2 limits for car manufacturers. But key details of the "health tourism" plan are still under fierce debate, The Times understands.

At present, rulings from the European Court of Justice allow NHS patients to demand swift treatment or scans abroad providing they are suffering "undue delays" on waiting lists.

One of the arguments is whether a patient needs to be on a long waiting list in order to qualify for treatment abroad, or whether they can simply demand overseas treatment straight away, in direct competition with the NHS. Ministers are concerned that this will lead to an uncontrollable loss of NHS funds abroad but supporters say it is just the kind of compertition the NHS needs to bring about improvements.

Last year, Britain reclaimed £38 million from other EU member states for treatment provided to their residents in this country, but paid out £526 million to other member states for treatment provided abroad.

Another point of contention is whether the patient needs prior authorisation from the NHS funding body, usually an NHS primary care trust, to travel in the first place. The draft proposals, seen by The Times, said that prior authorisation would not be needed for any out-patient treatment, meaning that patients could travel automatically, with a guarantee of reimbursement of all treatment costs.

But in-patient hospital care could be subject to prior approval if a member state made a clear case that a particular service would be undermined by too many patients travelling abroad automatically.

A third point of contention is whether patients could "top up" the NHS cost of their treatment in order to use NHS money as part payment for expensive private care abroad.

The directive is now due to be unveiled in January. But it will take more than a year to thrash out the final details because it has to be discussed by the European Parliament and then by ministers from every country in the EU Council.

The Government has vowed to fight to keep financial control - the right to approve the travel in advance - over all inpatient cases. Dawn Primarolo, the Health Minister, said that the Government would support proposals that did not undermine the principles of the NHS.

She added: "What we cannot allow and will not allow is that a few very wealthy patients choose to go elsewhere and then give the NHS the bill."

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