The trial of Constance Marten and Mark Gordon will not take place today after an electrical fire at the Old Bailey.

A loud band was heard and black acrid smoke billowed from an electrical substation near the rear of the building in central London yesterday morning.

Courtrooms were plunged into darkness due to the fire which halted all court proceedings on the day.

The Old Bailey will remain closed today for emergency repairs and is expected to open tomorrow.

Around 1,500 people were evacuated from the court as around 25 firefighters attended the blaze.

Dozens of barristers in their black gowns and wigs lined the street as four fire engines arrived.

The Argus: Defendants were escorted away from the court following the fireDefendants were escorted away from the court following the fire (Image: The Argus)

Later, defendants were seen being escorted by police and walked out of a side exit and into waiting prison vans to be returned to prison.

Barristers and other court users were told by security officials that they would not be allowed to go back inside to collect their belongings until safety checks had been carried out.

Constance Marten and Mark Gordon are accused of the manslaughter of their newborn baby daughter Victoria after going on the run before they were arrested near Brighton in February last year.