The chief inspector of prisons will warn John Reid today that jails are being placed under intolerable strain by having to cope with thousands of vulnerable women and mentally ill offenders who should be treated in the community.
Anne Owers' warning is likely to deepen the woes of the Home Secretary, who predicted yesterday that it could take until mid-2009 to overhaul his troubled department.
As he struggles to deal with the jail overcrowding crisis, a bitter dispute between the Prison Service and the Prison Officers' Association is also escalating.
In her fifth annual report Ms Owers will depict prisons as stretched to breaking-point by the pressures they face. More than 80,000 people are now locked up in England and Wales, a higher proportion than in any west European country. Ms Owers will warn that staff are finding it hard to cope with mentally ill and drug-addicted inmates and will raise the alarm over the numbers of women locked up for minor offences such as shoplifting.
She will also express concern over the number of offenders who are handed indeterminate prison sentences, which mean they can be held in custody indefinitely. And she will protest at the number of foreign national prisoners still in jail. Ms Owers will say that these factors are adding to overcrowding in jails and warn that rehabilitation work designed to stop offenders returning to crime is suffering as a result.
After three turbulent weeks at the Home Office, Mr Reid undertook a round of interviews yesterday to drive home the message that he was determined to see through sweeping reform of the department.
In an apparent sign that he expects to remain Home Secretary after Tony Blair steps down, he said the process could take another two and a half years. He told BBC Radio 4's Today programme: "I'm not daunted. I will see it through. If it needs endurance, if it needs determination, it will be there." Mr Reid likened the challenge he faced to the renovation of a house, when more problems can emerge as more rooms are refurbished.
David Davis, shadow Home Secretary, retorted: "Contrary to his claim, there is no evidence he is deliberately exposing the problems of the Home Office prior to solving them. Rather, he is papering over the cracks because he cannot solve them."
The dispute with prison officers centres on the staffing of a planned new 350-bed jail in Merseyside, with the union urging members not to co-operate with requests for officers to transfer from other jails on temporary contracts. The Prison Service is threatening to take court action against the union over the issue.
The International Centre for Prison Studies at King's College London, disclosed yesterday that the imprisonment rate in England and Wales was 148 per 100,000. It compares with 145 in Spain, 139 in Scotland, 128 in the Netherlands, 121 in Portugal, 105 in Austria, 104 in Italy, 95 in Germany, 91 in Belgium, 85 in France and 83 in Switzerland. The US has the world's highest prison population rate, 738 per 100,000, followed by Russia with 611.
Rob Allen, the director of the centre, said: "Excessive use of imprisonment does nothing to improve public safety."
Speaking in Downing Street yesterday, Tony Blair said: "Even though there has been tremendous progress, for example, on asylum or indeed fighting the battle against crime, there are a whole set of new issues that we need to deal with. Yes, it will be difficult, of course it will be difficult.
"But I have got no doubt at all they can be sorted out and will be over time, provided we are prepared to take the radical measures necessary to do it."
* People who involve children in prostitution or pornography will automatically go on the sex offenders register, under moves introduced by the Government yesterday. Courts will also have the discretion to place individuals on the register if they commit crimes such as kidnapping children or harassment offences, such as stealing underwear.