It argues that the pounds 500m that will have to be spent on providing new jails under government plans would be better targeted at crime prevention and detection, youth schemes and drug rehabilitation centres, which have been shown to be effective in the fight against crime and are under threat from public spending cuts.
The report published yesterday by the Prison Reform Trust has analysed the key justifications by Michael Howard, the Home Secretary, for giving courts wider powers to jail offenders in an attempt to halt the ever-rising crime rate. In contrast to some of his predecessors, who had concluded that 'prison was an expensive way of making bad people worse', Mr Howard's message has been 'prison works'. It provides retribution, deterrence, protection of the public and rehabilitation, he has claimed.
The study found little evidence to support those assertions. However, it was dismissed by Mr Howard, who said the trust was 'quite wrong to suggest that the Government's strategy on crime is 'almost entirely centred around the use of prisons'.'
He added: 'Our approach is comprehensive. The measures I am introducing are designed to prevent crime, enable the police to catch more criminals and to make it easier for the courts to convict the guilty.
'While they are in prison the public will be protected from their activities. And I have always made it clear that protection of the public is something to which I am determined to give very high priority.'
However, the study has concluded that the belief in the threat of custody as a deterrent fails to understand the impulsive, opportunist nature of most criminal activity - the Government's own 1990 White Paper, Crime, Justice and Protecting the Public, had argued 'their crimes are as impulsive as the rest of their feckless, sad or pathetic lives'. Since only 1 crime in 50 ended in a court conviction, experienced criminals were also unlikely to be deterred by the threat of tougher sentencing.
The report says the Home Office's own research unit estimated that it would require a 25 per cent increase in the prison population to cut the crime rate by 1 per cent and would cost pounds 1bn in new prison places. It says that there is only limited opportunity for rehabilitative work among offenders in jail and that the reconviction rates of those in custody have been consistently higher than those who have been punished in the community.
Adam Sampson, deputy director of the trust, said that the report was supported by evidence from abroad. In the United States, the prison population had more than doubled in the past decade and its crime rate - particularly violent crime - had continued to escalate. In Germany, a 20 per cent cut in the number of inmates produced no rise in crime.
'Crime is a complex phenomenon, born both from general economic conditions and from individual responsibility. By advancing prison as a solution to crime, ministers are misleading the public,' Mr Sampson said.