Jonathan Clifton is associate director for public services at IPPR.

David Cameron delivered a major speech on prisons today, promising to reduce re-offending and ‘offer hope’ to those who want to turn their lives around.

This is the latest step on his journey to capture the centre-ground of British politics. Already leading Labour on education policy, and having surprised them with devolution deals in their northern heartlands, the Prime Minister clearly has the criminal justice system next on his agenda.

The Prime Minister is right to flag up prisons as a ‘great progressive cause’ of our time. Our prisons are now in their most squalid and dangerous state for over a decade, according to the Chief Inspector of Prisons.

Britain locks up more people than any other Western European country and despite decades of increased incarceration, the re-offending rate for prisoners (especially those on short sentences) has hardly budged.

As Republicans are now arguing in many US states, it does not make sense to spend large amounts of taxpayer money on such an ineffective public service – especially when punishment and rehabilitation can be meted out in different ways.

The reforms proposed by the Prime Minister – which include rehabilitation league tables for prisons, more autonomy for prison governors, and a new graduate fast track programme for prison staff – read like a straight copy of the government’s school reforms. This is hardly a surprise since former education secretary, Michael Gove, is now in charge at the Ministry of Justice.

They all hold much promise for the prison system – giving governors stronger incentives and more freedom to tailor their prison regimes towards rehabilitation can only be a good thing. Anything that promotes transparency in our closed prison system should be welcomed.

But as Gove discovered with his school reforms, autonomy and league tables can only go so far in the face of major structural challenges.

Many of the problems facing our prison system are linked to factors that lie outside of the control of prison governors – such as the sentencing decisions made by courts, funding cuts to the ministry of justice, and the quality of probation and community services that could tackle the underlying causes of crime.

A genuinely radical and progressive prisons policy will therefore have to encompass these things as well.

Any reform in the current financial climate will have to involve sentencing decisions. While crime rates have fallen in Britain, the number of offenders being sentenced to jail, especially those on indeterminate sentences, has increased. Alongside funding cuts, this has led to overcrowding and chronic staff shortages in our prisons.

Yet improvements in technology mean that we are now able to provide effective punishment in other ways. The use of electronic tags, which now have more accurate GPS systems and can monitor alcohol and drug consumption in ‘real time’, means that sentences and curfews can be served in the community.

In the US, these approaches have been introduced alongside a swift ‘dunk’ back into prison for anyone who breaks the term of their sentence. Research has shown that for low level offenders, community sentences have lower re-offending rates than traditional prison sentences, showing that they can combine both punishment and rehabilitation for a lower cost to the taxpayer.

Policy must also focus on probation and community services that can tackle the underlying causes of crime. After all, prisons are only one piece of the jigsaw when it comes to reducing re-offending.

The Prison Reform Trust have laid bare the social ills which drive offending which show how, compared to the average population, our prisons have ten times the number of people who were in care as a child, four times the number of people with mental health problems, and three times the number of people with no qualifications.

Community services are important for helping ex-offenders to get their lives back on track, but they are starved of resources and local areas have few incentives to invest in them.

IPPR has argued that giving local leaders (such as City Mayors and Police and Crime Commissioners) more financial responsibility for prisons and probation could help to solve this problem.

If the cash spent on jailing low level offenders was devolved to local areas, local leaders would have both the resources and financial incentives to invest in programmes such as training, housing, drug and alcohol rehab, and mental health services.

If they were not successful at getting the prison population down, they would pick up the tab. This could be the next step for the Chancellors ‘devolution revolution’.

The Prime Minister’s focus on prisons is a welcome departure from decades of failed policy in this area, and gives a real boost to his claims of a ‘progressive conservativism’.

But if he is to cement his reputation as a progressive reformer, he will have to open up the more contentious issues of sentencing reform, community services, and devolving real power to local leaders over the criminal justice system.