Elstree doctor David Pugh faces up to ten years in jail after he admitted forging childrens' blood test results.

Pugh operated a private practice at Elstree Aerodrome, dispensing single-dose jabs for measles, mumps and rubella.

He told parents the £70 jabs were safer than the Government's combined MMR vaccine, but his operation fell apart after two doctors, Dr Andrew Eardley and Dr Adrian Waldron, told Hertsmere's NHS bosses that Pugh was making them give out-of-date, diluted, or poor quality jabs to children.

In February 2003, a national newspaper ran an expos on the scandal, revealing that up to 40,000 jabs given over ten years could have been faulty.

The next day a crowd of angry parents flocked to the clinic and demanded answers from Pugh, who then accused the NHS of persecuting him for offering an alternative to the MMR. In a desperate attempt to save his business Pugh offered to give the children blood tests, to prove they had been vaccinated.

On Monday, Pugh admitted that instead of sending out the genuine test results, he made photocopies of his 26-year-old daughter's results and sent them to parents.

He had been due to go on trial to face four counts of forgery, but changed his plea to guilty and will be sentenced next month.

Sharon Gold, from Anthony Road in Borehamwood, is still angry at Pugh for putting her son Joey's health at risk.

"Can you imagine how many children have been left unprotected?" she said. "I am worried there could be an epidemic in Hertfordshire now.

"I almost felt sorry for him at first, because I felt he was a scapegoat. Now I am just disgusted, and I hope he gets put away for a very long time."

Dr Joel Bonnet, director of public health at Hertsmere Primary Care Trust, said: "What he did was just not right, which is why we acted in the way we did."

He said parents who were concerned their children were not properly inoculated should take up the MMR vaccination, which had been used for more than 30 years and was considered safe by doctors around the world.

When the scandal over the faulty jabs was first exposed, Pugh sent a long, rambling letter to parents, which said: "We have carried out reliable antibody blood tests on 28 at-risk children. All of these children have been shown to be immune to the illnesses against which they were vaccinated."

It continued: "We would never endanger a child sic health in this way. No parent has ever filed a complaint, the only reactions notified are normal reactions to vaccination and none serious. We are horrified by the media's attempt to terrify and panic thousands of parents unnecessarily."

Mill Hill mother Denise Goldsmith is one of dozens of parents who plan to sue Pugh's medical insurers. Her son Noah contracted measles after being given a single jab vaccination at the clinic in September 2002.

"I'm relieved he's finally admitted this after the terrible, terrible ordeal we have been through in the last year-and-a-half," she said. "It's a huge relief to discover that we are not all raving mad. He was playing with children's lives. How can you do that?

"There are people in their 80s who have had him as a GP for thirty years. He was very well-trusted and respected. That's why we went to him in the first place.

"We thought he was trying to help everybody but in the end he was just being greedy."

Both whistleblowing doctors were sacked by Pugh for reporting their concerns to the NHS, but later received compensation totalling more than £100,000 at an employment tribunal.

Hertsmere Primary Care Trust is still counting the cost of the scandal. It set up a helpline for parents, enabling them to talk to NHS staff about the implications of their children being left unprotected.

"Our health visitors lost hundreds of man hours, they manned the phone lines for weeks taking calls from parents and guardians," said Dr Bonnet.

For information and advice about the MMR jab call NHS Direct on 0845 46 47.