The test case, which challenges the legality under human rights legislation of police interviews without legal representation, follows a decision in November last year by European judges in relation to an action in Turkey.

Hundreds of offenders are waiting for the outcome of the case and one lawyer last night revealed that his office alone already had 70 to 80 cases on hold until after the judgment is made.

Neil Hay, of MTM Defence Lawyers in Falkirk, said his firm had cases ranging from breach of the peace to serious sexual assault awaiting the outcome of the appeal hearing.

“There must be several hundred cases at least across Scotland which have been delayed and delayed waiting for an outcome on this,” said Mr Hay.

“In England you are entitled to see a solicitor but in Scotland it is entirely down to police discretion.

“I am not attacking the prosecution but am against the idea it should be up to the police.”

In a rare move, Scotland’s senior judge, the Lord Justice General, Lord Hamilton, sat yesterday with Lord Gill, the Lord Justice Clerk, and five other judges to decide on the case.

Lord Hamilton has already said he believes the issue is of “the first importance” for the country’s criminal justice system.

Under Scots law, a person suspected of an imprisonable offence can be questioned without the presence a lawyer for six hours, although they have the right to have a lawyer informed of their detention.

Police must inform the person that there is no obligation to answer questions.

However, in November last year the European Court of Human Rights ruled that Yusuf Salduz should have had immediate access to a lawyer when questioned by Turkish police.

Although the Salduz case was different to the standard Scots case, as it involved prolonged questioning by anti-terrorism officers, a case has been appealed from Forfar Sheriff Court to determine if the same principle applies here.

The losing side is then expected to appeal to the Judicial Committee of the Privy Council.

The Crown Office, which is in charge of prosecutions in Scotland, argues the matter was settled by the appeal court in 2000.

Then the court ruled that “neither Scots law nor the [European Convention on Human Rights (ECHR)] require that in all cases the person who is detained should be afforded the right to have his solicitor present”.

Duncan McLean, of Lethnot, Brechin, in Angus, is facing a trial at Forfar Sheriff Court accused of stealing a car and wilful fire-raising.

Lawyers acting for the 20-year-old have argued that to proceed with the prosecution would be incompatible with Mr McLean’s right to a fair trial under the ECHR.

He was detained by police in July last year and questioned by officers at Arbroath police station with neither a solicitor present nor the offer of legal representation.

The prosecution proposes to lead evidence at his trial about statements he made during the interview.

Chris Shead, Mr McLean’s counsel, told judges at the Court of Criminal Appeal in Edinburgh “the broad issue of principle” that arose was whether seeking to rely on that evidence would render the trial unfair.

Mr Shead said the ruling in the case of Salduz vs Turkey has since been followed in further cases against the Turkish authorities and other jurisdictions, including Poland.

Lawyers acting for Mr McLean argue that due to legal representation not being available from the moment he was taken into police custody, his human rights have been violated.

The judges are expected to give a decision at a later date.

How landmark rulings led to challenge

What is the Salduz case?

Yusuf Salduz, of Turkey, was arrested in 2001 on suspicion of taking part in an illegal demonstration in support of the imprisoned leader of the Kurdistan Workers’ party.

Salduz, who was under 18 at the time of the offence, was denied legal assistance while in custody, during which time he made a confession to police that he later claimed was under duress.

Almost 12 months ago, the Grand Chamber of the European Court of Human Rights ruled that Article 6 of the European Convention had been violated. It requires that “access to a lawyer should be provided as from the first interrogation of a suspect by the police,” unless there are “compelling reasons” to restrict this right.

The court ordered a re-trial.

Why does it affect Scotland?

Article Six of the European Convention on Human Rights makes explicit reference to the right to representation before and during a trial.

In Scotland, an accused person has no legal right to have a lawyer present to advise them when questioned by the police. Since 1984, in England and Wales an accused has had a legal right to have a lawyer present.

The case of Duncan McLean, which involves a charge of the theft of a motor vehicle, will be the test case after it was referred from Forfar Sheriff Court to the appeal court.

Why is there a panel of seven judges considering the case?

A panel of five judges considered the point in 2000 and ruled that Scotland was compliant. A seven-judge panel is now required to make a definitive ruling. It is unusual to have seven sitting.

In 2001, seven judges were asked to review a controversial decision by Lord Abernethy, which suggested that sex without the woman’s consent was not necessarily rape.

If the judges decide that Scots law breaches ECHR, what will happen next?

Both the defence team and the Crown have made clear that they will appeal the decision to the Privy Council in London if the judgment goes against them.

If the Privy Council agrees that Scots law currently breaches ECHR then hundreds and possibly thousands of offenders are expected to come forward to appeal their cases. In future it could mean detainees would have to be offered access to a lawyer.