Suspects face routine nationality quiz

The measure, being piloted by the Home Office, is designed to ensure offenders from overseas are identified early so they can be targeted for deportation.

It could also help detect the illegal immigrants who are causing the most disruption to communities.

Currently those detained by police are asked for details such as their name and address, but do not have to give information about their nationality.

The proposal would see suspects routinely quizzed on their nationality, what passport they hold, and whether it can be readily produced.

If they fail to answer the questions satisfactorily, the case can be passed to the Border and Immigration Agency for further investigation.

The material uncovered will remain on the police national computer even if the individual is never charged with any offence.

The Metropolitan Police has already started trials of the system in three London boroughs - Hillingdon, Waltham Forest and Westminster.

The project also involves the Crown Prosecution Service, Courts Service and the National Offender Management Service, and is due to run until December.

The Home Office was heavily criticised over the handling of foreign offenders last year, when it emerged that more than 1,000 had been released from prison without being considered for deportation on public safety grounds.

John Reid pledged to tighten up the system on taking charge of the department 12 months ago after Charles Clarke was sacked.

However, official figures released last week revealed that there are some 900 criminals in British jails whose nationality has not been established.

A Home Office spokeswoman said: "The requirement is for the police to identify known or suspected foreign nationals so the court can be told they could make a recommendation for deportation after conviction.

"This is intended to speed up the system.

"At the moment nationality is not checked until much later in the criminal justice process."