Overcrowded prisons are to blame for last year’s sharp increase in self-inflicted deaths among prisoners in England and Wales, it has been claimed.

The Howard League for Penal Reform (HLPR) has attacked the government after statistics revealed yesterday showed the number of convicts attempting to kill themselves increased to 92 in 2007 from 67 in 2006, a rise of 37 per cent.

The Ministry of Justice’s Deaths in Prison Custody 2007 report stated a high proportion of those who took their lives after harming themselves in prisons were “very vulnerable individuals”.

According to the HLPR, 45 per cent of those who died were either being held on remand, unsentenced or awaiting sentence after conviction.

It also claims the figure for female self-inflicted deaths rose by 133 per cent.

HLPR director Frances Crook said the 92 deaths should “sit uneasily” on government ministers’ consciences.

“The prison service has taken great strides in suicide prevention in recent years but it is all for naught when the system is on its knees with record overcrowding,” she commented.

“Staff and resources are strained to the limit coping with an ever-swelling prison population rife with mental health problems, drug and alcohol addiction and histories of neglect and abuse.”

Prisons minister Maria Eagle has ordered an inquiry into the reasons behind the increase. The probe, which will be headed by former Home Office minister Lord Bradley, will look into measures to improve security for those suffering from mental health problems.

Ms Eagle said she regretted the increase in prison custody deaths, adding that measures to halt the trend would be taken after considering the results of a review conducted by the Forum for Preventing Deaths in Custody.

Of the 92 deaths in custody, 84 were male prisoners and eight were female. The MoJ added that 130,000 prisoners went through the system each year and over 100 prisoners had been resuscitated after attempting to cause injury to themselves.

The MoJ defines prisoner ‘self-inflicted deaths’ as all deaths where it appears that a prisoner has acted specifically to take his or her own life. It states that approximately 20 per cent of these deaths will not receive a suicide or open verdict at inquest.