MPs are demanding answers from the Government and Buckinghamshire Hospitals' Trust management about why a deadly bug has been on the rampage at Stoke Mandeville Hospital for more than 18 months.

In a letter to the Health Secretary, Wycombe MP Paul Goodman said no hospital services should be moved from Wycombe Hospital to Stoke until an urgent safety review had been carried out at Stoke Mandeville.

Bucks Hospitals' Trust is reorganising services, centralising some at Stoke and some at Wycombe and Mr Goodman says this should not continue at present.

He asked the health secretary what her response was to staff claims that Government targets had got in the way of infection control.

He asked for figures about patients, staff visitors, mothers and babies. Since November 2003, when the hospital became aware it had a problem and started to audit the figures, 12 patients have died and almost 300 have been infected from clostridium difficile, the most common hospital acquired infection.

The last death was in January this year and the average age of those who died was 85.

Mr Goodman and Aylesbury MP David Lidington say the Government has questions to answer about whether the pressure put on the trust to hit NHS targets has led it to put health risks second.

Mr Lidington, who lives at Princes Risborough and whose four sons were born at Stoke Mandeville, said: "Thousands of patients will be wanting an explanation and a promise that everything necessary is being done."

Why, he asked, had this gone on so long?

He told the Free Press: "What I hear from staff is that targets get in the way of clinical priorities."

He said 90 per cent of the beds at Stoke were full, which was too high a proportion because it meant beds could not be taken out of service for disinfection and patients could not be isolated. He said he wanted to know whether hospital microbiologist Paul Gillette had retired because he could not have an isolation ward.

"You are talking about a hospital that is under huge pressure to hit targets and which as a result has not been able to get on with the job of dealing with this serious infection. "

Clostridium difficile can cause diarrhoea and inflammation of the colon, but generally responds to treatment. So it is not a drug-resistant superbug such as MRSA.

In March 2004 microbiologists at Stoke realised they were dealing with a more virulent strain of the bacterium, which produced severe symptoms.

The strain could be completely new or the same one which has killed more than a hundred people in Canada. Tests are being carried out but the hospital is not yet sure.

The hospital also says that about half the people who became ill had the more severe strain but that it does not know if the people who died all had this strain.

The number of patients infected is now dropping, from 24 in January to 17 last month, according to the hospital.

John Blakesby, the trust's acting chief executive, told the Free Press no young people or babies had died. The Health Protection Agency was working closely with Stoke's own infection control team.

"We shall follow their advice," he said. He said one of the hospital's two microbiologists had left, but this had been a planned early retirement.

A special ward has been set up for infected patients and protocols established for moving patients, for cleaning and for decontamination.

Trust staff have set up a hotline (01296 315539) to deal with all the calls