Yvonne was able to climb up the stairs after her operation

The High Court made the ruling after considering the case of arthritis sufferer Yvonne Watts, 72, who went to France for a hip replacement.

It ruled Mrs Watts had not waited long enough for compensation - but said others whose surgery had been delayed might be entitled to go abroad at the NHS's expense.

On Tuesday, Mr Justice Munby granted the Health Secretary John Reid leave to appeal - and Mrs Watts permission to cross appeal on various issues.

The judge was told that no final decision had yet been taken on whether to proceed with the appeal because the details of his judgment were still being considered.

In the judgment, which has major implications for NHS funding, the judge held that the current reimbursement system was unlawful because the existence of "undue delay" depended, not on a patient's clinical needs, but on whether a hospital was meeting its waiting list targets.

No common sense

He said an assertion by Health Secretary Dr John Reid, that no patient waiting less than the official 12-month target qualified for paid overseas treatment was incorrect

He described Dr Reid's claim that thousands would flood abroad and leave "overcapacity" in the NHS as "speculation unnourished by common sense"

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."

But he said Mrs Watts, of Queen's Park, Bedford, who had accused Bedford Primary Care Trust of unlawfully refusing to sanction funding for her French hip operation, did not qualify because she had eventually faced a delay of only three months at her local hospital.

He said the period of delay which was tolerable before it reached the level of "undue" was much less than a year, although more than the three or four months delay faced by Mrs Watts.

European law

Under European Community law E112 rule, any EU citizen suffering so-called "undue delays" in receiving treatment in their home country can apply to have the operation in another member state.

Mrs Watts required a hip replacement operation, and was initially told that the wait would be 12 months.

She shortened that time by paying for a private consultation and putting pressure on the hospital to move her up the list, but was still offered an eight month wait.

When she applied for authorisation to go abroad for treatment under the European Community rule, Bedford Primary Care Trust told her it was not necessary because it was meeting the Government's then target waiting time of 15 months for in-patient treatment.

It was at this point that she decided to book the operation abroad in a hospital in Abbeville, northern France.

Following this decision, the trust reviewed her case, decided it was more urgent and offered to carry out Mrs Watts' hip replacement within three to four months, despite a general in-patient waiting list of 12 months.

Mrs Watts was offered a "slot" on 6 May this year, but she chose to travel to France, where she had a right hip replacement on 7 March.

The High Court ruled that the fact her operation had been brought forward in this way meant that her own wait did not constitute an "undue delay" - and she should not receive any compensation.