One of the doctors struck off over the MMR jab controversy asked the High Court today to rule his treatment "unfair and unjust".
Professor John Walker-Smith is appealing against the General Medical Council's (GMC) determination that he was guilty of serious professional misconduct.
He is being supported by the parents of many children with autism and bowel disease seen by him at the Royal Free Hospital, north London, up to his retirement in 2001.
In a hearing expected to take 10 days, his lawyers are asking Mr Justice Mitting, sitting at London's High Court, to rule that he was denied a fair trial.
In May 2010, Prof Walker-Smith lost his license to practice along with Dr Andrew Wakefield, the doctor who triggered a global scare about the MMR vaccine.
A GMC fitness to practise panel found both guilty of misconduct over the way the research was conducted.
The panel's verdict followed 217 days of deliberation, making it the longest disciplinary case in the GMC's 152-year history.
It came 12 years after a 1998 paper in the Lancet suggested a link between the vaccine, bowel disease and autism - resulting in a plunge in the number of children having the vaccination.
In 2004, the Lancet announced a partial retraction, and 10 of the 13 authors disowned it.
Dr Wakefield was the paper's chief author and Professor Walker-Smith the then head of the department of paediatric gastroenterology at the Royal Free Hospital in north London, where the research was carried out.
Professor Walker-Smith's clinical role focussed on treatment related to sick children, while his academic work included collaborating in research with Dr Wakefield.
Aged 73 when struck off, Professor Walker-Smith had by then been retired for a decade.
But the panel said it had - "with regret" - decided that removing his name from the register was the "only appropriate sanction" for his "extensive failures", "non-compliance with ethical research requirements" and "irresponsible and misleading" reporting of the research findings.
A third doctor, Professor Simon Murch, who was a junior consultant in the department at the time, was cleared of serious professional misconduct because, although he had committed "errors of judgment" he had acted in good faith.
Grounds of appeal relied on by Professor Walker-Smith include assertions that the disciplinary proceedings were "unfair and produced an unjust result".
Stephen Miller QC, appearing for the professor, told the judge the "heart-breaking thing" about the Lancet paper - "whatever the reference made to MMR" - was that it was thought to be writing up "possibly exciting findings" with regard to bowel disease.
Mr Miller said it had been important that the disciplinary panel "separate out research from the clinical medicine - but that was a task that appeared to be beyond them".
The judge asked Mr Miller whether the alleged link between MMR and the vaccine "has now been utterly disproved" in the opinion of "respectable medical opinion".
Mr Miller said that was "exactly" the position.
Asked whether that was also the case in relation to autism and some types of bowel disorder, Mr Miller said: "There are still doubters and believers on that."
A campaign support group, Cryshame, said before today's hearing: "We are confident that Professor Walker-Smith will be found innocent of the findings the GMC has determined against him.
"The measure of British justice is tested by the way it treats a man of Professor Walker-Smith's stature following his distinguished and unblemished career."
Cryshame is a group of parents who say they saw their children regress into autism in their second year and ask why this happened, observing that there is currently no scientific explanation.
The parents say one consequence of the GMC's decision against the professor is that they now face serious difficulties in finding NHS treatment for autistic children with bowel disease.