Indefinite jail terms are indefensible – so why are thousands still trapped by them?

With the government’s Sentencing Bill currently being scrutinised in Westminster, it is opportune to ask why we are not removing what has been described by so many – including Lord Chancellors – as the stain of Imprisonment for Public Protection (IPP) on our system of justice.

Between 2005 and 2012, IPP – a novel and deeply flawed form of sentence – was imposed on over 6,000 people. It was a sentence of preventive detention which judges were required to impose for a wide range of crimes, even if they were not serious, provided that a statutory test of “dangerousness” was met.

Judges were also required to set the period of imprisonment that would otherwise have been imposed for the crime. This was then halved to produce what is known as a “tariff” – the minimum term an offender had to serve before they could be considered by the Parole Board for release.

The IPP sentence was abolished in 2012 after it was accepted to be a misconceived experiment. No one has received such a sentence since then. Yet, as the Howard League for Penal Reform has explained, and as The Independent has reported extensively, a significant number of those sentenced under IPP remain incarcerated.

At the end of September 2025, there were 2,422 people in prison on IPP sentences – 946 who had never been released, 1,476 who were released but later recalled, and more than 200 detained in mental hospitals.

Some cases are extraordinary in their disproportionality. Tariffs are intended to reflect the seriousness of the original offending. Yet one person received a nine-month tariff and has now served 20 years; another received a 330-day tariff and has served 17 years; one received a six-month tariff and has served 16-and-a-half years; and another received a tariff of three years and five months and has served 20 years. The sentence was even imposed on children – more than 20 of whom remain imprisoned decades later.

Since 2012, a number of proposals have been put forward to address this injustice, but all have been rejected. To its credit, the last government reduced the licence period for those eventually released.

But nothing has been done to help those who have never been released at all. Instead, ministers persist with a flawed IPP action plan – now in its 10th year – that is plainly failing. At a time when pressure on the prison system is so acute, the refusal to act is increasingly indefensible.

Last year, an expert working group convened by the Howard League explored how justice might finally be achieved. Its key recommendation was to modify the approach taken by the Parole Board in IPP cases.

Under the current test, the Board must decide whether continued detention is necessary for the protection of the public. We proposed instead that the Parole Board should be required to set a release date within a two-year window, and to specify what would be needed to achieve that safely – with a robust safety net for the most difficult cases.

I tabled an amendment to the Sentencing Bill to give effect to these recommendations. The government rejected it, claiming that it “will not take any steps that would put victims or the public at risk”. This claim does not withstand scrutiny.

First, the IPP sentence is now universally acknowledged to have been wrong in principle. How, then, can we as a nation continue to imprison people under a sentence that should never have existed? There is no convincing answer – only an unjust policy.

Second, those who committed the same kinds of offences before IPP was introduced in 2005, or after it was abolished in 2012, were and are released regardless of any risk they might pose. This alone exposes the government’s argument as untenable. What conceivable justice is there in discriminating against one group of people and refusing to correct the state’s own wrongdoing?

Third, psychiatric evidence is clear: imprisoning people indefinitely for offences that are not especially serious causes profound harm. IPP prisoners are placed at heightened risk precisely because their detention is unjust and hope is systematically extinguished.

The state must recognise that a grave mistake was made. If we can confront injustice in the Post Office and infected blood scandals, we can do so here.

Fourth, at a time of severe capacity crisis in our prisons, it is perverse to deny justice to those serving IPP sentences when doing so would free up around 2,500 prison places. The Sentencing Bill includes measures to deport foreign nationals who commit serious offences rather than imprison them.

What justice is there in allowing some offenders to avoid custody altogether while refusing even to consider the release of people who have long since served sentences far beyond their original tariffs?

Fifth, there remains a fundamental misunderstanding of IPP at the heart of the Ministry of Justice. The 2024-25 IPP annual report, produced by HM Prison and Probation Service, described the sentence as intended for high-risk offenders whose crimes were close to the threshold for life imprisonment. This is simply wrong.

As the short tariffs imposed demonstrate, many IPP prisoners committed offences nowhere near that level of seriousness. Subjecting them to the same release test as life prisoners is indefensible.

Allowing a failed action plan to trundle on, while refusing to deliver justice for those never released, ignores the urgency of the situation. People sentenced to IPP account for more than 3,000 incidents of self-harm in prison each year, and suicide rates among them are alarmingly high.

Parliamentarians should recall Winston Churchill’s observation that the treatment of crime and criminals is “one of the most unfailing tests of the civilisation of any country”.

This year, 2026, should be the year we finally pass that test. It must not be the year in which the government leaves the stain of IPP on our otherwise world-renowned justice system – and shows that we, as a country, are willing to tolerate an injustice we know to be wrong.

Lord Thomas of Cwmgiedd is a former Lord Chief Justice