Parents of children with autism have petitioned political leaders for urgent medical tests to be carried out into the safety of the MMR vaccine.

Despite repeated assurances from the Department of Health and the majority of medical opinion, some parents are still convinced that the vaccine may be responsible for some cases of autism.

For 20,000 kids to be seriously ill and not receive medical examinations is a national disgrace

Bill Welsh

Pressure groups handed petitions to Downing Street, the Scottish Parliament, the Welsh Assembly on Wednesday.

Not only do they want the government to fund urgent research into MMR, they are also calling for free access to clinical medical examinations and treatment for an estimated 20,000 children diagnosed since 1990 with autism.

Disgraceful

Bill Welsh, chairman of Action Against Autism, who is from Glasgow and grandfather of a seven-year-old boy with autism, said: "Research that is taking place at the moment does not reflect the urgent nature of this tragic episode.

"For 20,000 kids to be seriously ill and not receive medical examinations is a national disgrace.

"We believe these children are victims of medical politics - in other words, because the vaccination programme may be implicated in what has happened, the medical profession has turned its back on these cases."

Richard Miles, member of the Autism Research Campaign for Health, and father of a 13-year-old boy with autism, said: "We want treatment and we want to know why these children have the measles virus in their gut and blood."

The government has highlighted a series of studies which show no link between autism and MMR.

The group who came to hand over a petition at Downing Street included people whose children were not affected by autism, such as Dr Jayne Donegan from London.

She said: "We should be looking for answers rather than saying everything is safe, which is how the Government reacted to BSE and look what happened there.

"We don't want to have any more tragic, damaged children."

Heather Colvin, a care officer from Kentish Town in north London said she was lending her support as the confused parent of an eight-month-old girl.

"I don't trust what the Government says but I just don't know what to do about getting my daughter vaccinated."