Lucy Letby has now been in prison for more than 2,000 days, and during all that time nobody has come up with any evidence that she ever harmed anyone.

For more than a thousand of those days of darkness and misery, she was locked up as an unconvicted prisoner on remand.

Her sentence is in fact a death penalty, as she must die in prison. But it is a slow-motion death penalty, which the state lacks the courage to carry out quickly. It might take 50 years to kill her. It is far more cruel than any gallows, as that great liberal hero John Stuart Mill argued in 1865. She will be kept indefinitely ‘debarred from all pleasant sights and sounds, and cut off from all earthly hope’.

Yet what evidence there was against her – all of it circumstantial and vague – has now been entirely demolished by experts, or has blown up in the faces of those who gave it.

Imagine that – more than 2,000 days without a free breath. Yet the Criminal Cases Review Commission (CCRC) is still pondering away.

I am surprised that Britain’s mighty and influential feminist movement has yet to take up this matter.

The case began when Ms Letby stood up to (senior, male) colleagues who were making damaging suggestions against her.

What’s more, she is in an even worse predicament than a man in the same position would face. She will be 37 in January. If she is in fact not guilty of the appalling murders she is supposed to have committed, there is very little time left for her chances of a remotely normal life.

Let me put this bluntly: If she is eventually exonerated, and is released after it is too late for her to have a child, the state will have robbed her and her family of something so unutterably precious and irreplaceable that nothing could ever compensate for it – no apology, however grovelling, no payment, however large.

There is no time to waste here. If she is to stay in prison, we must know that her confinement there is justified by a lot more than the heap of maybes alleged against her.

And yet the latest rumour is that we may know by Christmas what the CCRC has decided. I agree, it is only rumour, but I have seldom known a case questioned and challenged at such a high level by so many people who know what they are talking about, ranged against a conviction that to this day lacks a single hard fact in its favour.

And if the CCRC says that her Appeal should at last be heard (she has twice, astoundingly, been refused permission to appeal), how long will that take?

I have been among scores of people, almost all of them unrewarded, without any connection to Ms Letby, who have spent many months researching this case, and concluding that, to put it mildly, the conviction is unsafe.

Even the Crown Prosecution Service recently rejected an attempt by Cheshire Police to bring new charges against her. Maybe someone in authority is beginning to realise that she was swept into her cell on a tide of presumed guilt, and never got the fair trial that is supposed to be the birthright of us all.

These failed charges were similar in character to the ones on which she was first convicted. Something has changed. And yet the great rusty black cast-iron slowly-clicking mechanism of English law has barely turned an inch.

Why the delay? For nearly two years now experts – statisticians, engineers, highly-qualified doctors of neonatology, former police officers, a retired Supreme Court judge and two former cabinet ministers – have been over this case and found it wanting.

Yet there are still many beliefs about it, which somehow persist whatever critics of the prosecution say. I know from many conversations that these things are still widely believed. For example:

1. ‘She confessed’. No, she didn’t. This claim is made based on one of many anguished and contradictory scrawls she made, while undergoing therapy after being accused. She has always denied the accusations.

2. ‘She was caught red-handed’. No, she wasn’t. Nobody actually said this, because no such thing took place. The phrase ‘virtually red-handed’ was used at one stage. But the doctor involved in this claim has since been found to have given a totally different e-mail account of the event, much more favourable to Ms Letby.

3. ‘She was the only person on medical staff present at all the deaths of babies in the Chester hospital during the period in question’. No, she wasn’t. There were other baby deaths on the unit during this time. She was not present for some of them.

4. ‘The deaths stopped after she was removed from the ward’. This is a half-truth, and a very misleading one, a glaring example of one of the most basic errors in logic, that if A happens after B, A must be caused by B. The deaths also stopped after the ward was downgraded to take less serious cases.

All the supposed methods by which she is alleged to have killed babies – causing an air embolism, for example – are theories that might explain the deaths, though other experts, led by the eminent neonatologist Shoo Lee, say that there are far better explanations in the low quality of the hospital and its levels of care and hygiene. These problems are, to put it mildly, not unknown in NHS establishments, much less rare than motiveless mad killers.

Indeed, no one has ever suggested a motive for Ms Letby’s alleged crimes. Her friends remain loyal to her and say there is nothing in her character to suggest she could have done these things.

And then there is the suggestion that Ms Letby attempted to poison babies by putting deadly doses of insulin in feed-bags.

Many believe this was crucial in persuading the jury she was guilty. The prosecution told jurors at Letby’s trial there could be no doubt that these were not accidents, but poisonings.

Yet the quality of the evidence for these alleged poisonings is scientifically weak. And a new research paper by Professor Geoff Chase, a bioengineer and specialist in insulin delivery, and his colleague Helen Shannon, a chemical engineer, say that there is grave doubt that extra insulin was ever given to the babies involved at all.

Many supporters of the prosecution have long argued that the insulin claim was ‘the smoking gun’ that convicted Ms Letby. But now there is a strong suggestion that that gun was not smoking. It was in fact not even loaded.

Reopen the case, now, for the Love of God.