If cabinet minister and Oxford East MP Andrew Smith needed a new hip, he would have to wait longer for treatment in his constituency than anywhere else in Oxfordshire, according to a parliamentary website.

The Associate Parliamentary Health Forum has pinpointed the average amount of time patients have to wait for surgery in a number of UK constituencies.

Although the average wait nationally for a hip replacement is 239 days, Mr Smith, the Chief Secretary to the Treasury, would probably have to wait between 227 and 250 days.

MPs in other areas of the county could progress more quickly through the health system.

Banbury MP Tony Baldry could have the shortest wait, with an average of 151 to 200 days for his operation. But Liberal Democrat Dr Evan Harris, of Oxford West and Abingdon, and Conservatives David Cameron, of Witney, and Boris Johnson, of Henley, could all wait between 201 and 226 days. Health managers in the county were unable to explain the differences.

NHS hip replacement patients in Oxfordshire are usually treated at the Nuffield Orthopaedic Centre in Headington, Oxford -- in Mr Smith's constituency.

Last year, 750 patients underwent the operation at the NOC, representing almost a 10th of all surgery at the hospital.

There are 472 people waiting for similar treatment at the hospital.

Staff could not explain why there were differences in waiting times in different parts of Oxfordshire, according to the website. The website is compiled from information provided by health analysis company Dr Foster.

The data, from March 2001, is collected from NHS statistics and evaluated by postcode areas.

A NOC spokesman said: "It is very difficult to comment on the figures as they date back to March 2001 and were compiled using different methods than those used by us.

"It is possible that a small sample size has distorted the figures for a particular area.

"The Nuffield Orthopaedic Centre is continuing to reduce waiting times for our patients by modernising and reviewing our working practices."

The Associate Parliamentary Health Forum website was set up by a cross-party group, and is only accessible by politicians.