Demonstrations are being held outside a Crown Court where a Keighley grandmother is accused of plotting to damage a Trident submarine while it was waiting to be tested in dock.

Campaigner Sylvia Boyes, 57, of Keighley, and Open University tutor River, 45, formerly known as Keith Wright, are on trial at Manchester Crown Court after denying a charge of conspiring to commit criminal damage.

The duo, who were yesterday due to give evidence, are members of the disarmament group Trident Ploughshares which aims to bring about the end of all nuclear weapons.

The trial heard that the pair set out to damage the submarine Vengeance while it was being prepared to undergo sea trials at Barrow shipyard, Cumbria, in November, 1999.

The jury, of six men and six women, was told that the activists were caught equipped with hammers and an axe before they had a chance to swim to the submarine.

Elizabeth Nicholls, prosecuting, told the jury: "I am sure that whatever the outcome of this trial you will conclude your jury service with a feeling of utter respect and admiration for the strength and integrity of these two defendants' beliefs. For there is no doubt that these two people do hold very strong opinions as to the evils of nuclear weapons."

Miss Nicholls said the defendants were both members of a group called Trident Ploughshares which wanted to bring about the end of all nuclear weapons.

The court heard that the defendants were found on November 23 when security guards searched the shipyard after talking to a film crew.

Mrs Boyes was found first, wearing a hooded wet suit, with a hammer and screwdriver attached to her belt bearing anti-nuclear slogans. River was then found in the water in a similar wet suit equipped with hammers, a small axe and wire cutters. He also had six cans of aerosol varnish.

After the pair were arrested the court heard that they were taken to a nearby police station where they read from a pre-prepared statement when questioned. Documents were also found in River's possession clearly confirming their membership of the anti-nuclear group.

Miss Nicholls said the pair believed they were acting lawfully because they believed being in possession of a nuclear submarine was a crime and unlawful.

The trial continues.