A fateful day, under a different kind of justice , but the judges are by due process of a differnt law another kind of justice nears its conclusion

This Sunday in a courtroom in al-Khobar, Saudi Arabia, two British nurses are on trial for their lives. Sources close to the case confirmed yesterday that the brother of the murder victim, Yvonne Gilford, had not used a three-week adjournment to intercede on their behalf. Meanwhile Deborah Parry and Lucille McLauchlan are preparing once again to proclaim to the three judges, all devout Muslims and scholars in Islamic law, their innocence of a crime to which they confessed just before Christmas in a statement which they now say was extracted under brutal police pressure just after their arrest.

Even for a high profile case involving British citizens abroad, the trial has attracted an exceptionally high level of diplomatic activity. Yesterday Baroness Symons, the Foreign Office minister responsible for consular affairs, met both the defendants' families, who remain utterly convinced of the two women's innocence. So, increasingly, are a number of close observers of the case.

Australian government officials have been discreetly in touch with Frank Gilford, the victim's brother. The case is being closely monitored by senior British officials and Robin Cook, the Foreign Secretary has been given regular reports. William Patey, the British consul general, will attend the hearing, along with the Saudi legal adviser, normally retained by the embassy, Salah Al-Hejailan, who is representing the defendants. But British officials say that the Saudi authorities have been scrupulous in ensuring consular access to the defendants and accepting the role - historically unusual in such criminal cases - of lawyers in the court. And the Saudi ambassador in London, who yesterday spoke exclusively to The Independent about the trial, is also keeping in close touch with developments.

None of this is surprising, when you consider how high the stakes are. In the most extreme scenario, the two women face the possibility of public beheading, an outcome which would provoke an outcry here of the sort which could well threaten diplomatic, strategic and above all commercial relations with Saudi Arabia. UK visible exports, 25 per cent of them in arms, totalled pounds 2.5bn last year. Imports, mainly of oil, totalled around pounds 752m. It is a safe bet that neither country would want that relationship disrupted; but it is an equally safe bet first that the British government would come under public pressure to apply diplomatic sanctions against Saudi Arabia, and second that inflammatory things would be said and written here which might well prompt the Saudis to do the same in reverse.

When in 1980 the BBC broadcast its film Death of a Princess, showing the execution of a Saudi princess for adultery, there was a full-scale diplomatic row which went on for four months, and a trade battle which went on for even longer. British public opinion is impervious to the regular beheadings in Saudi Arabia of Pakistanis, Nigerians or Bangladeshis, often for drug smuggling offences; but it would almost certainly react very differently to the execution of two British women protesting their innocence.

Yvonne Gilford's body was found on 11 December on the floor of her flat in the King Fahd Military Medical complex in Dahran where she worked as a nurse. . She had been stabbed, bludgeoned and suffocated. The prosecution claims - and this is vigorously denied by both the defendants - that she had been involved in a lesbian relationship with at least one of them, that during a late-night argument one of the nurses hit her with a teapot, and that she drew her knife to protect herself. In the ensuing scuffle, it is alleged, the knife was snatched from her and she was stabbed, suffering multiple wounds in her head, chest and arms. As she screamed out, she was then allegedly suffocated with a pillow. And finally, it is alleged that one of the two women was spotted using the victim's cash machine card in a local dispenser.

Most of that version surfaced in the now disavowed confessions. The nurses now say that they signed the confessions only after being stripped naked and fondled, and that policemen had trod on their feet. They have indicated they were at once threatened with rape if they did not sign confessions, and promised that as non-Muslims charged with a crime against another non-Muslim they could be assured of avoiding Sharia justice, with its ultimate penalty of beheading, if they did.

On Christmas Eve they were allowed to see a British consul from Riyadh for the first time. In a second meeting four days later the women said that that their confessions had been extracted under duress and that they were false. British officials reported their claim to the Saudi authorities who said there was "no medical evidence" of assault, and the case went to two hearings of the court in May at which the women continued to be adamant that their original confessions were untrue. At the last hearing on 25 May, the court was adjourned for three weeks to allow time for Mr Gilford to say whether he would, in the event of a guilty verdict, press for the death penalty.

To understand that development it is necessary to understand how Islamic law differs from most Western systems. In family or tribal feuds, where murder is committed the penalty - either Qisas (execution) or the payment of blood money - is settled between the parties. That even happens in some cases, according to British observers, where the question of guilt has not yet been established. Mr Gilford, used to an Anglo-Saxon system of justice, appears to be reluctant to pronounce on the sentence, at least before there has been a verdict.

And in this he has the sympathy of Dr Ghazi Algosaibi, poet, novelist and the Saudi ambassador in London, who said yesterday that the court had still to examine the evidence and he himself found it "bewildering to ask a man to forgive something before the question of guilt or innocence is established". The lawyers in the case, he suggested, had "opted for a strategy of preventive clemency which obviously didn't work".

In an interview at his embassy in Mayfair, Dr Algosaibi insisted there was no question of the earlier confessions swaying the judges if the two defendants continued to disavow them, and that the court would be scrupulous in not condemning the two women unless they had sufficient evidence of their guilt. Asked about the fact that the women were kept in police custody for several days, during which they complain confessions were extracted under duress, he said: "I don't want to comment on the allegations made by the girls or their lawyers. All I can say is that regardless of any confessions given to the police, the court will judge the case on its merits."

British observers are concerned that one of the three judges who will be in court on Sunday also heard the original confessions. But Dr Algosaibi was adamant that if the confessions were claimed to have been extracted by pressure or was retracted "the court will ignore the confessions presented by the police. It will only uphold a confession if it is given in front of the court."

It was normal for Islamic judges in cases of serious crime to give the defendants every chance to affirm their innocence. In a system which does not usually employ lawyers, the judge acts as defence counsel, jury and judge combined. "They will start their examination by saying, `you didn't do this did you, you didn't confess that did you?' The judge is responsible directly to God. He believes that if he condemns an innocent man he will be severely punished by God. The last thing he wants to do is simply accommodate any police force ... A judge who condemns am innocent man to death will consider himself a murderer."

Dr Algosaibi rejected another British worry that women over their mid- thirties who are not married are assumed in Muslim countries to be lesbians (and that in this case lesbianism is a key part of the motive attributed to the two women). "There is no such assumption at all," he insisted.

Dr Algosaibi has refused visas to British reporters and television crews seeking to travel to Saudi for the trial because he is worried about the tabloid and network circus inflaming sensitivities about the case. But he refused to be drawn on the possible diplomatic and trade consequences of a death penalty. "I cannot speculate about a situation where guilt has not been determined. This is such a hypothetical situation. What if a Saudi citizen assassinated Tony Blair? No one has asssinated Tony Blair. Two girls have not been convicted."

It is common ground between both the British and Saudi authorities first that a very high degree of certainty will be necessary if the judges were to sanction the death penalty; but secondly that unless, as seems unlikely, the judges decide to free the two women on Sunday, the process still has a long way to go. First the hearing in the al- Khobar court could be adjounred and resumed for several more hearings. Then a range of verdicts from not guilty to guilty of anything from intentional crime to unintentional or accidental crime could be delivered. Only intentional crime, in which self-defence or an accident during a scuffle is not a cause, can attract the death penalty.

Dr Algosaibi emphasised that other evidence beyond the confessions would be needed - and British lawyers have no details of any evidence the prosecution may bring on Sunday. And finally, there is a lengthy - up to two years - appeal procedure first to Tamijeez court, the equivalent of the Court of Appeal, and then to the Supreme Court of the five most senior judges in Saudi Arabia. It is then up to the King to give the go-ahead for the death penalty, though in such private cases of murder, Dr Alogsaibi, said, the King has the power only to delay execution if the death penalty is upheld by all the courts, not to cancel it.

There is every reason for hoping it will not come to that. But if it does, Frank Gilford has the power of life and death in his hands.