Representing the rights of everyone involved in a case is a balancing act

Adversarial versus Inquisitorial - these three words have been at the centre of repeated debates over the years, on the very essence of the UK's Criminal Justice System.

This week the subject has hit the headlines again, with proposals from the detective who led the Damilola Taylor murder investigation for crucial changes to the way the courts deal with vulnerable witnesses.

Detective Superintendent Tony Crofts' suggestions would essentially mean introducing mainland European-style elements of an inquisitorial system into Britain's existing adversarial one.

Public contest

The United Kingdom currently operates a wholly adversarial legal system.

This means the trial process - where a not guilty plea is entered - is effectively an oral and public contest between the opposing prosecution and defence sides.

Investigations are made by both sides before the trial, and the judge listens to the arguments. The judge, or jury if one is required for the case, will reach a decision based on those arguments and the cross-examinations of defendants, victims and witnesses.

Existing aids for vulnerable witnesses: Screens to hide defendant from witness Communication aids eg alphabet boards Live TV links Removing wigs and gowns Clearing public gallery Listen to Radio 4 special programme

Although a number of measures have been introduced recently to help victims and witnesses, including children, they can still be subjected to interrogation in court.

In a sexual offences case in Scotland in 2001, an 11-year-old girl was cross-examined over 10 days by six defence lawyers. Her brother was reduced to tears twice while giving evidence via a live television link.

The trial collapsed after a child psychologist advised that the boy could be seriously damaged if he continued to give evidence.

Supt Crofts has called for vulnerable witnesses to be questioned only by a judge, or mediator, as is practice in most of the rest of Europe under the inquisitorial system.

Judge decides

Options being considered: Video-recorded evidence Pre-trial cross-examination on video Use of intermediaries in court

In countries such as France, the majority of evidence is gathered by the judge before the trial, which weeds out weaker cases before it goes public.

Without a jury, the judge questions the accused and witnesses then decides whether the defendant is guilty. Prosecution and defence parties can ask supplementary questions.

Children are rarely called to give evidence at the trial, but if they are the judge controls questioning by the defendant's advocates.

Supporters of the system argue the judge's influence reduces the level of "contest" found in the British system, where both parties are free to present their case as they see fit.

'Test evidence'

In response to this week's proposals, child law specialist Allan Levy QC has opposed such a reform.

He told BBC News 24 that it was the responsibility of the Crown Prosecution Service and police officers to determine whether a witness was reliable, and only present them if they found that to be the case.

You can't add an inquisitorial bit to a very strong adversarial system Allan Levy QC

He said the 12-year-old witness in the Damilola case was used as a "forensic sacrifice" because those involved in bringing her to court must have known how unreliable she was.

He is strongly in favour of retaining the current system.

"The defence is entitled to test the evidence," he said.

"You can't add an inquisitorial bit to a very strong adversarial system."

Campaigners calling for a change include Paddy Hill, of the Birmingham Six, who claims the system should be replaced with an inquisitorial system where the emphasis is on the "search for the truth".

In 1993 a Royal Commission examined the relative merits of both systems, and concluded that England and Wales should not move to an inquisitorial one.

A new Criminal Justice Bill: Justice For All is currently going through the House of Lords.

The government says it puts the needs of victims and witnesses "at its heart".

The Scottish Parliament is currently consulting on the Vulnerable Witnesses (Scotland) Bill, which aims to provide better protection for children and adults likely to be frightened or distressed at giving evidence.