A High Court judge says that, in principle, at least, if you have suffered "undue delay" waiting for your NHS operation, you can go to Europe, have surgery - and leave the NHS to pick up the bill.
Yvonne Watts took her case to the High Court
The grandmother, Yvonne Watts, who brought the case paid almost £4,000 to go to Lille for a hip replacement.
She actually lost her personal claim for compensation on Wednesday, simply because she would not have had to wait much longer for her UK operation.
However, there are fears that the ruling could lead to a frail stampede across the Channel into the arms of the French and German healthcare systems.
The government says no-one should be waiting more than 12 months for inpatient operations such as hip and knee replacements or cataract surgery.
Health Secretary Dr John Reid said that anyone waiting less than a year would not see a penny off the NHS if they dared set foot in a foreign hospital.
Judge James Munby put him straight on that point - if there was "undue delay", regardless of arbitrary waiting list limits set by ministers, the NHS should pay up for treatment abroad.
"I have decided in principle that the claimant is correct
and the Secretary of State is wrong," the judge said.
Regardless of this, however, there remains a good deal of confusion about what the ruling actually means to patients - and the wider NHS.
It does not offer a new option to patients - simply agrees with an existing one.
Under European Community law, we are all, as citizens of an EU state, entitled to travel elsewhere in the community for our treatment if we suffer this "undue delay" at home.
Applying to the NHS under "E112 certification" for this right is not all that common, and, as Mrs Watts found, current guidance from the Department of Health leaves many obstacles in the path of the would-be traveller.
It is still unclear the precise level of demand from patients - many of them elderly - to leave their home towns and travel hundreds of miles from family and friends for their operations.
According to the figures for the first quarter of 2003-4, there were 67,000 patients waiting for 6 months or more for trauma and orthopaedics - about 20,000 of these waiting 9-11 months.
Only a handful of patients now wait more than 12 months.
Dr Reid said he feared the "spectre of overcapacity" in the NHS as thousands deserted our health service for foreign shores.
Judge James Munby was rather scathing about this - no-one would choose this path except as a last resort, he said.
"Common sense suggest that those who go abroad make that choice only because
of the delays which they currently experience in the NHS," he said.
What the ruling does is make clear that there is no fixed limit - such as 12 months, or 15 at the time of Mrs Watts' operation - which designates whether someone has been waiting too long or not.
This is not entirely surprising - even government ministers say that their current 12 month maximum is unsatisfactory, and want it cut in half over the next few years.
Even a handful of months may be classed as "undue delay" if you have a treatable condition that leaves you in daily agony, and which is likely to deteriorate rapidly over a short period.
But the judgement does not suggest a general figure - in the case of Mrs Watts, her wait of a few months was reasonable, it was ruled - but waiting as long as a year would be "undue delay".
This means that every single applicant who wants to stare at hospital walls in Lyon next week rather than London in June next year would have to be assessed individually.
For some, two months might be too long, for others, a year would not be a problem.
This raises the prospect of introducing fresh bureaucracy of the type for which the NHS has traditionally been famous.
Michael Sobanja, the chief executive of the NHS Alliance, represents the hundreds of Primary Care Trusts which have to decide how NHS money is divided.
He said: "All this ruling does is leave us in no man's land - with an open chequebook open to challenge on every occasion.
How long a wait is too long?
"All it will do is mean we have to spend a huge amount on legal fees."
He said that, in his view, the Department of Health should return to the Court of Appeal and seek urgent clarification of the issue - then hand out their own guidelines.
He said that the immediate impact of the ruling would be to raise patient expectation through the roof.
"Many patients are perfectly prepared to travel abroad to have operations, and they will apply to do it."
The unfortunate side of the whole matter for the NHS is that ministers are not opposed to tackling "problem" waiting lists by sending patients abroad - or bringing in foreign surgery teams to treat them here.
It plans to introduce, eventually, a system which will allow any patient waiting more than six months for an operation a choice of venue for the operation, be it elsewhere in the NHS or a selection of foreign centres.
This would be run in a controlled way, with bulk contracts for overseas providers, not piecemeal - with every individual patient sending themselves somewhere different.
That scheme has yet to emerge - but a flurry of bills from European hospitals landing on the UK's doormat could certainly bring it to the top of the agenda.