Former Cabinet Minister to spearhead campaign raising questions over the conviction of killer nurse Lucy Letby as growing numbers of experts express concerns about her case

Former Cabinet Minister David Davis is to spearhead a Commons campaign raising questions about the conviction of nurse Lucy Letby as growing numbers of experts express concerns about the case.

The ex-Brexit Secretary plans to table a series of questions under Parliamentary privilege amid disquiet within the NHS and the legal profession about the case.

Mail columnists Peter Hitchens and Nadine Dorries have highlighted that Letby was convicted of the murders of seven newborns and the attempted murders of six other infants at the Countess of Chester Hospital, despite the fact that no one saw her kill, or attempt to kill, a baby and there is no forensic evidence to prove her guilt.

Two witnesses for the Crown, basing their views on a 30-year-old research paper, suggested that Letby murdered babies by injecting them with air through their feeding tubes. 

However, the Canadian academic who wrote the original paper was not called as a prosecution witness and has since cast doubt on his work being used in the trial.

Some members of the Royal Statistical Society have expressed concerns over the use of statistics to secure a conviction on the basis of probabilities. Its recommendations on using such data in the cases of medical serial killers were not followed here.

Separate prosecution claims that Letby killed two babies with insulin were summarised in a damning investigation by The New Yorker magazine as: 'One would have to believe that she had managed to inject insulin into a bag that a different nurse had randomly chosen from the unit's refrigerator.'

Mr Davis is understood to be concerned about the justice system's institutional reluctance to admit to its own failings, leading innocent people to languish in prison. 

He said: 'There is a mounting consensus among experts that Lucy Letby's guilt was not established beyond reasonable doubt. I will be using Parliamentary privilege to raise these arguments: we must exclude the possibility that she has effectively been scapegoated for the wider failings in the system.

'At the very least, this appears to be a mistrial But the justice system moves slowly when it comes to assessing its own failings, so if she is innocent it could be a decade before she is released. We must try to do much better than that.'

Helen Pitcher, the head of the Criminal Cases Review Commission, refused to resign last week despite a damning report into the watchdog's handling of the case of Andrew Malkinson, who spent 17 years in jail after being wrongly convicted of rape in 2004.

Dr Alexander Coward, a former Oxford maths lecture, has questioned data used in the trial which showed Letby on shift at every death and attempted murder, saying that could easily have happened by chance.

Ex-MP Edmund Bulmer, former chairman of the Herefordshire Health Authority, previously told Rishi Sunak he believed Letby was 'the victim of a monstrous miscarriage of justice'.