The European Court of Human Rights in Strasbourg will give judgment this Thursday on claims brought by Robert Thompson and Jon Venables against the British Government.

The two boys were aged 10 when they murdered two-year-old James Bulger in 1993. They were sentenced to 15 years in detention. The boys lawyers' say they were not given a fair trial.

Legal affairs correspondent Joshua Rozenberg looks at what the court will have to decide.

Robert Thompson and Jon Venables claim there has been a breach of their human rights. There are three key issues for the court:

• Did they have a fair trial?
• Should their minimum punishment period have been fixed by the Home Secretary?
• Should their case have been reviewed sooner?

These questions were considered by the European Commission of Human Rights last year. Under a procedure that's now been abolished, the Commission used to filter cases before they reached the Human Rights Court. The commission published its opinion on 15 March 1999.

Fair trial

Article 6 of the Human Rights Convention says everyone is entitled to a fair hearing. Thompson and Venables said they were denied a fair trial because their case was held in an adult court. The Human Rights Commission agreed. In the commission's opinion, the two 11-year-old boys were not able to participate effectively in their trial.

If the Human Rights Court reaches the same conclusion, it will be a serious defeat for English justice. Nobody would like to think that two particularly vulnerable defendants were deprived of a fair trial on such grave charges.

However, lawyers think it unlikely that Thompson and Venables will win on this point. They think the Strasbourg court will get round the issue by saying that lawyers for the two boys should have complained at the time: they could have asked for the public to be excluded from the courtroom. They did not do so and the boys did not appeal against their convictions.

Home secretary's role

Article 6 of the Human Rights Convention not only says that everyone is entitled to a fair hearing; it also insists that the fair hearing must be by an independent and impartial tribunal.

In English law, a child aged 10 or over who has been convicted of murder must be sentenced to indefinite detention. The minimum period the child serves in detention for the purposes of punishment and deterrence is called 'the tariff'.

That tariff is set by the Home Secretary. He receives advice from the trial judge and the Lord Chief Justice, but he does not have to follow it.

The former Home Secretary Michael Howard set a tariff of 15 years for Thompson and Venables. Jack Straw agreed to set a new tariff following a successful challenge in the House of Lords; partly because he had to wait to hear from Thompson's solicitors, he has not yet done so.

Fixing a tariff

Lawyers for Thompson and Venables argued that fixing a tariff should be seen as part of the court process. On that basis, the tariff should be set by an independent and impartial tribunal. The Home Secretary's legal team did not try to argue that a government minister could be seen as independent.

The Human Rights Commission was almost unanimous in agreeing with Thompson and Venables on this argument. It said "the fixing of the punitive element must be regarded as part of the sentencing procedure".

The British Government is widely expected to lose this point when the Human Rights Court gives its ruling. If that happens, tariffs will have to be set by courts rather than politicians in future.

It is not yet clear what impact this would have on Thompson and Venables. Mr Straw could regard himself as bound to follow the tariff set by the judge who presided over their trial, which was eight years. Or he could ask a tribunal such as the Parole Board to set a new tariff.

But a further point made by Thompson and Venables means that even eight years could turn out to be too long.

Review after five years

Article 5 of the Human Rights Convention says everyone who is deprived of his liberty shall be able to have the lawfulness of his detention decided by a court.

Thompson and Venables said that meant they should have their case reviewed regularly. The Human Rights Commission agreed. By the time of its report, a year ago, they had already been detained for five years.

"Five years for an applicant sentenced at age 11 must be regarded as a long period of time," said the Commission. It concluded, again almost unanimously, that the British Government had broken Article 5 of the convention.

If the court shares that view, there will certainly have to be regular reviews for children sentenced to indefinite detention. The commission said that, for a young child, "only a short tariff could be compatible with Article 5".

If the court agrees, then in future it's possible that no judge would be able to impose a tariff of more than five years on a child who commits murder.