Both magistrates and probation officers are indicating their extreme reluctance to fit offenders with tags that place them under electronically monitored house arrest.
Their lack of co-operation could wreck the three pilot projects which are due to begin on 5 June in Reading, Norfolk and Manchester.
The Magistrates' Association has issued guidance saying that tagging should not be used as an alternative to prison. It added that tags should also not be fitted to people who: have chaotic and undisciplined lives; are likely to tear off the tag and run away; or have domestic problems likely to be exacerbated by house arrest. "Most magistrates would say that that list covers the majority of offenders before the courts," Rosemary Thomson, the association chairman, said last week.
The National Association of Probation Officers (Napo) said it would tell its members never to ask the courts to use tagging. Last month two chief probation officers visited the United States to see how tagging worked. "The main message is that electronic monitoring in the US is a shambles," their unpublished report concluded.
When the Home Office last pilot-tested tagging, in 1989, the courts were persuaded to tag just 49 offenders in six months. The majority of these ran away or committed other crimes or both.
But Mr Howard still believes curfews can work. In his forthcoming £1.4m trials, offenders can be ordered to stay at home for 12 hours a day for up to six months.
They will have a tag fitted to their wrists or arms, and a transmitter in their homes will sound an alarm in the monitoring centres - run by private security companies - if they leave.
The preparatory work is being done under conditions of great secrecy in Walton-on-Thames and Norfolk. Both Securicor, in Walton, and Geografix, a Norfolk technology company which developed homing devices so that stolen yachts and JCB earthmovers could be traced, refused last week to give any details of the monitoring systems they are preparing.
Ministers and Downing Street share their caution. There is a fervent belief in Whitehall that by placing offenders under an electronic monitored house arrest the Government will seem tough on crime.
But they expect criticism. Last week the Downing Street Policy Unit ordered the Home Office to prepare what civil servants described as a "defensive briefing" for use in June.
The Home Office has claimed that there is no reason why tagging should not work in Britain. Electronics companies have told officials that between "200,000 and 250,000" people were tagged in the US.
Chief probation officers said that when they went to the US, they discovered that the number of offenders tagged was between 20,000 and 40,000. Numbers were falling, they said, because the costs of fitting the tags and monitoring the offenders were far higher than expected and the use of technology had failed to lower the prison population.
The technology is very sophisticated. There are tagging units developed by Mitsubishi and Digital which transmit pictures of the criminal from his home.
One system reads criminals' alcohol levels - although the US courts have accepted that cough mixture and mouthwash can distort the results and give the impression that sober men are drunk.
But, reported the chief probation officers, tags cannot not cope with "the human element". Poor offenders, on drugs or without work and decent housing, simply broke the curfew.
In most cases, it was only middle-class offenders with good homes and settled families who successfully completed two- to six-week periods of house arrest.
Senior American criminologists at the National Institute of Corrections and the National Council on Crime and Delinquency told the British probation officers that support for tags was opportunist.
They were used because "politicians and administrators need to say they are getting tough on crime," one told the British delegation.
Another said:"If we could start again we would never do what we have done. It seems inconceivable that Britain is going to repeat exactly the same mistakes."
Harry Fletcher, assistant general secretary of Napo, said: "The Government does not understand that people are not like earthmovers.
"The only time that tagging succeeds in the US and Canada is when it is imposed for short periods on middle-class petty offenders who are not much of a threat to society."
A Home Office spokeswoman said that the criticisms missed the point that tagging was being tested in a pilot project and the Government would carefully evaluate the results before deciding whether it would be launched nationally.Reuse content