Speaking openly about the case, he claims that revelations in the documents could amount to a bundle of smoking guns and a couple of cases of hand grenades. They would expose the precise ways in which Michael Howard and his ministers involved themselves in the minutiae of the day-to-day running of internal prison matters. In the Commons, Michael Howard declared that he set the policy and was not responsible for operational matters. As a result, the buck stopped with Derek Lewis, who was summarily fired last October (following Sir John Learmont's report into the Whitemoor and Parkhurst escapes), and not with the minister who stayed firmly in place.
The papers will throw light into some murky and controversial corners concerning the question of just how much "arm's length" independence the Prison Service - a much heralded Next Steps agency, supposedly beyond the daily control of the Home Office - really has. Lewis is calling for the minutes of meetings which, he says, will show how he was summoned virtually every day to the Home Office by one minister or another interfering in operational matters. In 83 days, 1,000 briefing documents were called for by ministers. He says, "Most of them originated with a story in the press which the minister wanted to respond to for political reasons."
Lewis gives some graphic examples of ministerial interference. Documents, he says, will show that the Home Secretary personally intervened in the question of where Private Lee Clegg was held, following an embarrassing, right-wing press campaign to free him. He claims that for political reasons Howard wanted Clegg moved to an open prison. Ministers are not supposed to recommend preferential treatment for prisoners.
Lewis says the papers will show that ministers challenged the punishments meted out to particular prisoners - a matter that is the sole legal prerogative of prison governors. He says, "In a case where one prisoner had telephoned the media, a minister intervened to try to get a tougher punishment imposed on him." Home leave decisions for individual prisoners are, by statute, decided by the governor; but again, Lewis claims, Howard intervened. He also claims there was interference in the disciplining of staff, when the minister wanted someone fired.
All these and much more, Lewis says, will be revealed in court. After all, he knows exactly what papers to ask for, because he was there at the meetings and party to the correspondence. On the matter of his own sacking, he believes Michael Howard made the decision arbitrarily on his own. "The Home Secretary's decision to dismiss me was against the very strong advice of others in the Home Office, including the board and its non-executive directors." He will ask for the minutes of all meetings and directions given to General Learmont by Howard in the course of drawing up the report that led to Lewis's downfall.
In the Commons Michael Howard defended his decision with a quick stiletto stab between the ribs, claiming Lewis' complaints were merely "the spleen of a bitter man". Lewis replies "I am not bitter", but he wants justice, plus some pounds 75,000 in compensation.
Civil Service observers are amazed that the Home Office has taken this case so far down the line. There are many who presumed that the Home Secretary would rapidly settle out of court and face a lesser embarrassment rather than full disclosure of these sensitive documents.
Derek Lewis is an unlikely rebel. He seemed a strange choice for the prisons job when he was head-hunted, in 1993, from the chairmanship of UK Gold, the satellite TV station, to which he has returned. Appointed somewhat high-handedly by the then Home Secretary, Kenneth Clarke, the First Division Association, the top civil servants' union, protested vigorously. Now they are defending him with equal vim.
Lewis has been through a Damascean transformation. I first met him when he was safely ensconced as director of prisons. He had summoned me for a private briefing following a fairly abusive article I had written. As deep background, non-attributably and off the record, he told me in total confidence what a super job he was doing and how jolly well the prisons were performing. I prodded and goaded him about the Home Secretary's "Prison Works" policy - a soaring prison population combined with financial cuts. If there was a gleam in the eye that suggested he might agree, not an improper word passed his lips.
Now he blisters with criticism of the danger in which Michael Howard is placing the creaking prison system, with longer sentences and a return to gross overcrowding. This, it must be said, is intellectually a tricky balancing act. On the one hand, he points out that he did a first- rate job, meeting every performance target he was set (and therefore earned his as yet unpaid bonus). He broke the back of the Prison Officers' Association and abolished their Spanish practices. He cut violent assaults by 10 per cent and escapes by 83 per cent. On the other hand, it seems, he was efficiently administering what he knew to be a disastrous policy.
Now, like Cassandra, he stands outside the prison walls shaking his fist and warning of the conflagration to come, an eruption of brimstone that may soon engulf the Home Secretary. Month by month prison numbers continue to rise - a prisons press officer confirmed rather jauntily yesterday, "Yes, it's at an all-time high! This week it stands at 53,357," as if it were the roll-over jackpot. That number is 25 per cent up, nearly 10,000 more than when Howard took office, all due entirely to his personal policies.
Each prisoner costs nearly pounds 2,000 a month. To pay for it, two weeks after sacking Lewis, Howard cut back the prison service by 15 per cent over three years, cuts that Lewis fears will lead to an explosion as prisoners are locked up for long hours, without education or work. "Prisons only work with the consent of the majority of prisoners. It is a dangerous and difficult balance," he warns. "And there is absolutely no evidence that longer sentences mean less crime."
When Derek Lewis's case comes to court, the questions will have to be answered. Where does the buck stop? Who is accountable? What is the precise division between "operational" and "policy" matters? Does it amount to anything more than subterfuge? Now you see the minister, now you don't. In the wake of the Scott report, when civil servants face disciplinary proceedings while ministers escape punishment, this case may prove an added embarrassment.
The First Division Association says Howard has been strongly advised by his officials to settle, but he is reluctant. If he pays out the performance bonus due to Lewis, he will have to admit that Lewis met all his targets and his sacking was an arbitrary act.
In the end Mr Howard may yet decide it would be wiser to pay up the pounds 75,000. After all, that's only the cost of keeping a mere 38 people in prison for a month. For a man paying out tax payers' money to keep an extra 10,000 as Her Majesty's guests, that is peanuts.