"A minimum level of legal representation": Stephen Jessel reports from Paris

About 70 lawyers and scores of defendants left the makeshift court when a plea to have proceedings postponed was refused.

The defence teams had argued their clients would not get individual justice in a mass trial.

They also want the hearing moved from its current venue - a gymnasium belonging to the prison authorities - to a normal court.

French anti-terrorist operations intensified after the Paris Metro bombing

The trial of 138 people charged with operating a support network for radical Algerian Islamist groups is the largest of its kind in France.

Defendants are said to have provided weapons, shelter and false papers for groups including the Armed Islamic Group (GIA).

The first day of the trial on Tuesday got off to a bad start when a number of defendants failed to turn up.

Four of the 27 defendants held in custody refused to attend court. Some of those not being held in jail also failed to turn up at the specially converted gymnasium outside Paris.

Alleged Islamist network leaders

Most of the defendants were arrested in France, in November 1994 and June 1995.

Defence lawyer Alain Mikowski: "Being judged 5m from the largest jail in Europe""

Among them is Mohammed Kerroushe, or Salim, extradited from Britain last year and alleged to be the head of Islamist networks in Europe.

Also in the dock is Mohammed Chalabi, another suspected leader of an organisation involved in helping the Islamists in Algeria.

Most suspects were arrested in security operations in 1994 and 1995

If found guilty of "criminal association with a terrorist enterprise", the defendants face up to 10 years in prison.

Correspondents say the gymnasium was chosen because the courtrooms of the Palais de Justice in central Paris, were too small to accommodate the proceedings.

The trial is expected to last two months.