A woman aged 72 who went to France for a desperately needed hip replacement operation that cost her £3,800 took the NHS to court yesterday, seeking her money back.

Yvonne Watts, of Bedford, claims she is entitled under European law to receive funding for treatment abroad if there is "undue delay" in this country.

She was told by a consultant last October that she would have to wait up to 15 months for a hip replacement operation on the NHS, or could have it done privately in the UK within a week for £8,000.

The Government launched a scheme last summer to treat some urgent cases abroad to relieve pressure on waiting lists. But when Mrs Watts applied for authorisation to go abroad for treatment under the NHS's E112 certificate scheme, the trust told her that it was not necessary because it was meeting the Government's target waiting time of 15 months for inpatient treatment.

Mrs Watts had the surgery at the St Isabelle hospital in Abbeville, Normandy, on 7 March. In addition to asking the NHS to pay for that operation, which cost the same as it would have on the health service, she is asking the state to fund the same treatment on her other hip.

She is accusing her local hospital trust and Alan Milburn, the Health Secretary, of unlawfully refusing to sanction the funding for the foreign treatment, against European laws. If she succeeds there could be major implications for hospital waiting lists and NHS funding.

The key would be the judge's decision on the definition of "undue delay".

Her counsel, Richard Gordon QC, argued yesterday that to decide the issue of "undue delay" by reference to the waiting-list target was wrong.