The Department of Health's review of autism, the first study of scientific evidence to include lay people, faced collapse last week, as hostility to the proceedings came to a head.

Although the review findings are not due out until November, it is expected to conclude there is no proven link between the condition and immunisation offered to children for measles, mumps and rubella, and there is strong evidence autism has genetic triggers, even if the exact genes involved have not been identified.

However, campaigners do not believe this, and last week some rejected the set of experts chosen by the review, arguing they are biased.

Such reviews of evidence are normal practice for medical science - where scientists establish what has, by a reasonable estimation, been proven about a particular condition's causes or incidence.

Twice now, the Medical Research Council has looked at the alleged links between autism and concluded there is no real evidence that a relationship exists with the MMR vaccine.

However, these findings have not convinced many parents, worried by reports of the vaccine triggering the onset of the psychological disorder.

Because public concern has grown, ministers at the Department of Health asked the MRC to include the public, and campaigning groups, in a new review, not just of MMR, but everything known about autism.

Project manager for the MRC's review Dr Peter Dukes, however, remains upbeat about the review, and said he was relieved members of the public involved have now written a general letter saying they fully supported it.

Even if it takes five times as long as the average review, he argues it could reap very real rewards.

"They bring their experience and their view of what the important things to research are. Also, they feel a greater sense of confidence in the final report and can transmit it through their networks and groups. What comes out at the end is that some lay people will better understand the nature of scientific evidence," Dr Dukes said.