The findings from a public inquiry into how nurse Lucy Letby was able to repeatedly murder and harm babies will be published on Tuesday. The Thirlwall Inquiry was established to examine events at the Countess of Chester Hospital between 2015 and 2016, during Letby's tenure in the neonatal unit.

Letby, aged 36, is currently serving 15 whole-life prison sentences for the murders of seven infants and the attempted murders of seven others. The inquiry's scope did not extend to determining Letby's guilt but rather focused on the hospital's handling of concerns raised about her and whether earlier interventions could have prevented the harm.

A key question the report is expected to address is whether any of the babies' deaths or injuries could have been avoided if action had been taken sooner. Letby was moved to administrative duties in July 2016 following concerns raised by consultants to the hospital's executive team. However, the inquiry has investigated whether earlier warning signs, such as the deaths of three babies in quick succession in June 2015, should have triggered a more immediate response.

The inquiry, chaired by senior judge Lady Justice Thirlwall, heard six months of evidence and reviewed thousands of documents, costing over £18.5 million. It is anticipated that the report will identify significant safeguarding failures and propose changes for the wider NHS.

The chairwoman of the Criminal Cases Review Commission (CCRC), the body with the authority to refer Letby's case back to the Court of Appeal, stated that the CCRC will be closely reviewing the report's findings. Letby has previously been denied permission to appeal her convictions on two separate occasions.

Letby's defence lawyer, Mark McDonald, informed BBC Newsnight on Monday that nearly 30 expert reports have been submitted to the CCRC, which he claims "undermine the whole safety of the convictions" and represent more evidence than in any other CCRC case.

McDonald added that if Letby is innocent, as he and the experts believe, then the inquiry's premise and recommendations may be based on a false foundation. He expressed sadness over the departure of two experts from his team, Prof Geoff Chase and Helen Shannon, who withdrew after citing inconsistencies between the proposed arguments and available evidence. Despite their withdrawal, McDonald maintained that these experts still believe in Letby's innocence, stating their departure was due to a belief that their own arguments were stronger.

Letby's defence team has faced challenges with expert support, as two previously engaged experts withdrew from the case. Prof Geoff Chase and chemical engineer Helen Shannon reportedly left after claiming some evidence presented was inconsistent with scientific findings. McDonald acknowledged their departure but reiterated his belief in Letby's innocence, suggesting the experts disagreed on the strength of the arguments rather than her guilt.