Two members of an international expert panel that had backed Lucy Letby's innocence claim have withdrawn their support, warning that her barrister Mark McDonald is now damaging her chances of overturning her convictions. Helen Shannon, a British chemical engineering expert, and Professor Geoff Chase, a New Zealand-based bioengineering academic, said they still believed it "very unlikely" that two babies were deliberately poisoned with insulin, but could not endorse other strands of evidence being advanced by the defence, citing "scientific credibility" concerns and "unresolvable problems". This matters because the evidence forms part of a dossier submitted to the Criminal Cases Review Commission (CCRC), which is assessing whether Letby's case should be referred back to the courts.

Letby, 36, is serving 15 whole-life terms after being convicted at Manchester Crown Court of murdering seven babies and attempting to murder seven others at the Countess of Chester Hospital between June 2015 and June 2016, and continues to protest her innocence. The withdrawing experts, writing to the CCRC, said some arguments now being pursued were "inconsistent with the available evidence, science and established physiology" and accused McDonald's strategy of putting Letby's "long-term interests" at "serious, unnecessary and unacceptable risk", with consequences also affecting victims' families. The panel had been led by Canadian neonatologist Dr Shoo Lee, whose independence was earlier questioned after he described the group as potentially Letby's "last hope"; McDonald has separately been reported to the Bar Standards Board.