John Wadham of Liberty: "Danger that ex-offenders will suffer unnecessary discrimination"

The certificates will be issued by a new Criminal Records Bureau, details of which were announced by the Home Office on Monday.

The primary aim would be to stop sex offenders or other serious criminals working with children or in unsuitable positions.

But it will be open to any employer to ask potential recruits or existing workers to produce a document listing their current convictions.

At the moment, criminal record checks are only carried out by the police and usually only on public service employees working in areas such as schools, probation services or with under 18-year-olds in other fields.

Three levels of checks

The strictest checks will apply to those seeking work with children, in gaming or the judiciary

The new bureau will be run by the UK Passport Agency, offering three levels of checks. The most stringent, an "enhanced criminal record certificate", will be available for workers regularly caring for under-18s, those in the gaming and lottery sectors, or in the judiciary.

It will contain the applicant's entire criminal record history - including spent and unspent convictions - as well as details of all cautions and even police intelligence from ongoing operations.

The next level, the "criminal records certificate", will be available to people in regular contact with under-18s, the elderly, sick or handicapped, law enforcers and others in sensitive professions.

This will also contain details of spent and unspent convictions but only cautions for offences which could result in prison sentences.

However, the third level document, the criminal conviction certificate, will be available to anyone and any employer can ask to see it. It will set out only unspent convictions.

Most convictions are spent after up to 10 years depending on the seriousness of the crime and age of defendant, but any that lead to a prison sentence of 30 months or more remain for life.

10 million certificates a year

Paul Boateng: The certificates "should become part of following up references"

The government estimates around 10 million certificates will be issued every year by the bureau.

Legislation for setting up the agency - which will take about two years to get fully up and running - which will be based in Merseyside and create around 1,200 jobs, was set out in the Police Act 1997.

Announcing the plans, Home Office Minister Paul Boateng said it was expected that checking someone's criminal record would be seen as part of the process of following up references.

A code of conduct would be issued to employers to prevent abuse in terms of refusing jobs to people with criminal convictions. Mr Boateng said at the moment employers could ask for details of criminal records.

This process simply enabled them to verify the information given to them and recruits would be able to apply to an industrial tribunal in the same way as they could presently if they felt they had been treated unfairly.

He said: "This sends out the message that a responsible employer will carry out checks and the level of check will reflect the degree of potential risk."

Civil liberties alarm

The new plans have provoked concern that the certificates will make it harder for ex-offenders to find work. Civil liberties groups are also alarmed at the implications. Helen Edwards, chief executive of the National Association for the Care and Resettlement of Offenders, warned against "sweeping" plans to give employers access to records about convictions which might have little relevance to the job in question.

"If ex-offenders find it significantly harder to find jobs, this will increase the likelihood of reoffending and damage the fight against crime."

John Wadham, director of the civil rights organisation Liberty, said: "Because about 35% of all men have a criminal record, disclosure can act as a significant additional punishment and can undermine efforts to re-integrate ex-offenders into society.

"Ex-offenders without work are more likely to re-offend than those in work. We believe there is a danger that ex-offenders will suffer from unnecessary and unjustified discrimination."