Former Home Secretary, Michael Howard, delivered an astonishing and controversial rebuke to the coalition's penal policies in a speech in London on Monday night.
At the Carlton Club's Carlton Lecture, which in the past has been delivered by sitting Prime Ministers, including Margaret Thatcher, the former Conservative party leader, now in the House of Lords as Lord Howard of Lympne, openly criticised the current Justice Secretary, Ken Clarke, by repeating his 1993 mantra, "prison works".
In June 2010, Ken Clarke attacked the "Victorian bang 'em up" prison culture in what the Guardian described as a "major assault" on Lord Howard's "prison works orthodoxy".
Mr Clarke had said that the prison population was rising out of control and needed to be checked. When he was Home Secretary for two years (1992-93) prior to Michael Howard, the number of prisoners in England and Wales was 44,628. He described the current figure of 85,000 as "an astonishing number which I would have dismissed as an impossible and ridiculous prediction if it had been put to me in a forecast in 1992."
Lord Howard gave his own insight into Whitehall predictions, saying that when he took over the Home Office in 1993 he was told that the job of a Home Secretary is "to manage public expectations about crime, which will always continue to rise" - usually by 5% every year. Adopting a triumphalist tone, Lord Howard said that he had reversed this defeatist trend - and he arrived armed with the statistics to show it.
Lord Howard said that during his tenure as Home Secretary, crime fell on a sustained basis for the first time since the First World War. A consensus was reached between the Conservative party and New Labour that prison worked: as the prison population increased, crime fell by an unprecedented 18%.
"Alas," said Lord Howard, "That consensus was broken when Ken Clarke was astonished to discover how much the prison population had risen."
"I believe in evidence based policy", claimed Lord Howard, "and there is no objective evidence for [Ken Clarke's] alternative theories." One that he mentioned was Mr Clarke's claim that crime rates have fallen as a result of an economic boom - instigated, perhaps ironically, during Clarke's tenure as Chancellor of the Exchequer during the 1990s. As evidence, Lord Howard claimed that despite unemployment rising sharply following the onset of the financial crisis in 2008/09, crime continue to fall.
Mr Clarke was attacked again for his claim that falling crime rates are a global phenomenon, again presumably linked to global prosperity. However, Lord Howard cited evidence from Canada, the Netherlands, the United States and Scotland to contradict him, then said that in Northern Ireland the prison population had fallen but crime simultaneously had increased.
Italy, said Lord Howard, is "particularly interesting". In 2006, the Italian Parliament passed a 'Collective Clemency Bill', which set free all prisoners with less than three years left on their sentences. One-third of the prison population was released. Recorded crime then rose from 2.4 million to 2.9 million.
The reasons Lord Howard gave for the fall in crime during his time as Home Secretary included greater encouragement to use CCTV and the first DNA database in the world - both policies that the current coalition government is regulating more tightly as part of a wider emphasis on greater civil liberties.
Lord Howard's is the latest in a long line of attacks on the Justice Secretary's bold attempts to cut costs in the justice budget and reform Britain's broken penal system. Mr Clarke has incurred the ire of everyone from the Tory right-wing to red-top tabloids to legal aid campaigners - some would say unfairly so too.
At the recent Conservative party conference, the Justice Secretary had a public falling out with Home Secretary Theresa May over the Human Rights Act, a gay Bolivian immigrant and his cat. Despite Ken appearing to be largely justified in his criticisms - if not the public way that he expressed them - the Prime Minister gave Mrs May his full support. Mr Clarke is also currently under fire for sentencing reforms that are being portrayed in parts of the media as weak and likely to send less people to prison - a specific example of the general criticism levelled at him last night by Lord Howard.
In a rare conciliatory moment, Lord Howard said that he agreed with and supported Ken Clarke's "rehabilitation revolution", stating in something of a departure from his previous tone, "no one wants people to be sent to prison for the sake of it", "prison is not an antidote to recidivism" and "too many people re-offend".
Yet it was only a momentary departure, for he went on to criticise Mr Clarke's very objectives: "We should no longer judge the success of our justice system by a fall in prison population." Lord Howard believes that the correlation between lower crime and a higher prison population is clear.
"It is beyond reasonable doubt," concluded Lord Howard, "and on the evidence, the coalition has been found wanting".
"I strongly support the Government's re-offending revolution and I hope that it succeeds but given the statistical evidence it has little prospect of doing so".