Evidence of Lucy Letby's guilt was "compelling and overwhelming" the prosecution's chief medical expert has said, after he was accused of being an unreliable witness.
Dr Dewi Evans spoke after Letby's barrister said he would seek a fresh appeal on the grounds that Dr Evans changed his mind about how three babies in the case had died.
The retired paediatrician from Carmarthen gave press interviews following the verdicts claiming that the mode of death was different to his original findings.
He also prepared a new report on the death of Baby C - a baby boy who died in June 2015 - which has been handed to Cheshire Police but not disclosed to Letby's defence.
Mark McDonald, the barrister for the former nurse convicted of murdering the babies, held a press conference on Monday to announce he was seeking a new appeal.
However, in a statement released on Tuesday morning, Dr Evans said that he was still convinced of Letby's guilt and would happily take the stand again.
"If required I would be pleased to give evidence in the usual way," Dr Evans said. "Mr Mark McDonald's observations regarding my evidence are unsubstantiated, unfounded, inaccurate.
"His method of presenting his information reflects clear prejudice and bias. I cannot recall any KC advocating on behalf of a client via a press conference, especially a case of such sensitivity.
"I find his style most unedifying, most unprofessional. It's highly disrespectful to the families of babies murdered and harmed by Lucy Letby."
Dr Evans originally said that three babies - anonymised at trial as I, P and C - were killed by an injection of air into the stomach. He has since changed his mind to say it was likely to be air injected into a vein.
However, Dr Evans said evidence of Letby's guilt in the case of Baby I - a girl who died in October 2015 - remained "compelling and overwhelming", while evidence in the case of Baby P - a boy who died in June 2016 - was "consistent and considerable".
Dr Evans said that Letby had carried out a "murderous assault" on Baby C.
Mr McDonald told the press conference in London on Monday that he would take the "unprecedented" step of asking the Court of Appeal to review all her convictions based on Dr Evans's re-evaluation of the cases.
Mr McDonald said: "I have never known - in 26 years of being a barrister - an expert to change their mind a year after the convictions on the cause of death, or what they said to the jury. That, to me, is astonishing.
"The defence will argue that Dr Evans is not a reliable expert, and given that he was the lead expert for the prosecution, we say that all the convictions are unsafe."
But Dr Evans said three appeal court judges had already "provided a very thorough review of the evidence" and had denied Letby leave to appeal.
"They were supportive of my evidence," he added. "They supported the verdict of the Manchester trial unreservedly. I am not in receipt of any information that indicates that the Appeal Court judges were mistaken."
Letby, 34, of Hereford, is serving 14 whole-life terms after being convicted of murdering seven babies and attempting to murder seven more at the Countess of Chester Hospital in 2015 and 2016.
Mr McDonald said he had "50 or 60 experts" working free of charge to review the evidence against the former nurse. As well as asking for an appeal, he is planning to take the case to the Criminal Cases Review Commission.
On Monday, it emerged that two neonatal experts had reviewed the cases of babies O and C and found "no evidence of deliberate harm".
Dr Neil Aiton and Dr Svilena Dimitrova, NHS consultants who are working on the case as independent experts, said they had found "identifiable medical reasons" why both babies became unwell and did not respond to resuscitation.
Dr Richard Taylor - a neonatologist from Victoria, British Columbia, who often helps police inquiries - told the press conference he believed Baby O died after a needle was wrongly inserted into his liver by a doctor on the neonatal unit.
Chester Police are currently investigating more deaths and collapses of babies at the Countess of Chester and Liverpool Women's hospitals and have not ruled out bringing further charges. Letby was interviewed in prison earlier this month.