More than 215,000 prisoners are to be freed from jail early in the next seven years, according to projections of the prison population published yesterday.

The number to be freed is calculated on the assumption that an emergency early release scheme, introduced last year to deal with jail overcrowding, continues indefinitely.

In the first year of the scheme, under which nonviolent offenders are freed 18 days before their sentence ends, 31,500 criminals in England and Wales left jail early. David Hanson, the Prisons Minister, said that when there was enough capacity in the overcrowded prison system the emergency scheme could be rescinded.

Prison Service sources said, however, that it was likely to be years before there was enough new accommodation to allow the scheme to be ended.

The latest figures from the Ministry of Justice suggest that the prison population will rise to 95,800 by 2015 at the top end of estimates, or 83,400 at the bottom end. The figures are substantially lower than last year’s projections, which suggested that by 2014 the prison population would be higher than the politically sensitive figure of 100,000 at the top end and at 88,800 at the lower end. The current prison population of 83,518 is already above the lowest projection for 2015.

Broadly, the latest figures suggest a jail population 6,000 lower than last year’s projections - the result of measures taken by the Government to cope with overcrowding. These include reform of the new indeterminate sentence for public protection, which will reduce the number given the sentence from 140 a month to 45. Prisoners who break the terms of their release and are returned to jail will automatically be released after 28 days. At present they stay in jail until the end of the original sentence or the Parole Board agrees their release.

Also, prisoners given electronic tags while on remand will be able to count that amount of time against their sentence.

Edward Garnier, the Shadow Justice Minister, said: “The sharp reduction in the expected number of prisoners has nothing to do with crime going down and everything to do with this Government’s incompetence in managing our prisons.

“To hide the truth, they have simply passed more laws to limit the ability of judges and magistrates to give custodial sentences, replaced the laws they passed to ensure more people went to prison for longer, and then released more and more prisoners early.

“When early release was introduced, we were promised it was ‘very temporary’. Now we are told that officials assume it will continue indefinitely.” The Government has started a huge prison-building programme to tackle the jail overcrowding crisis and to enable it to meet future demand for prison places.

Overall, 20,000 new prison spaces are to be provided by 2014, including provision at the three giant, and highly controversial, so-called Titan prisons, with each holding 2,500 inmates.

Frances Crook, director of the Howard League for Penal Reform, said: “Given current sentencing trends, these revised figures are blindly optimistic. The Government needs to take off the rose-tinted glasses and institute a wholesale review of the penal system.”

Times Recommends

• An officer and a gentle woman
• Dame Helen Mirren is worthy of the Epidaurus
• Foods that can help to prevent swine flu