A couple whose baby daughter died after experimental treatment have won a victory in a fight to have action taken against the doctors that treated her.
Professor Southall was one of three doctors named in the case
Court of Appeal judges ruled the GMC should review its decision to reject complaints from Carl and Debbie Henshall, of Clayton in Staffordshire.
The three doctors involved carried out trials using experimental breathing tanks designed for premature babies.
The couple said the trials were linked to the death of two-day-old Stacey.
They also said the trials led to another daughter suffering brain damage.
A new hearing has been ordered early next year to decide how the ruling can be put into effect.
The Henshalls had already failed twice to force a disciplinary hearing against Professor David Southall, Dr Martin Samuels and Dr Andrew Spencer.
The three specialists had worked on hospital trials into the
controversial CNEP treatment - negative pressure chambers used in the early
1990s to try to help sick, premature babies breathe without the need for
Mr and Mrs Henshall allege the health specialists did not give properly informed
consent to medics for their girls to be placed into the CNEP tanks.
The Appeal Court judges will hear argument early in the new year from legal representatives for Dr Spencer and Dr Samuels - and possibly from Professor Southall - as to whether Mrs Henshall's complaints should now be sent back to the GMC for reconsideration.
Lord Justice Sedley and Lord Justice Parker agreed that the "only fair outcome" now was Mrs Henshall's complaints to be referred back to the PPC for reconsideration.
The legal aid-funded action comes a week after Prof Southall survived a legal move by a health watchdog body to have him struck off over an unrelated matter.
He has previously been found guilty of serious professional misconduct after accusing a man of murdering his sons on the basis of a TV programme he had seen.