The pair cut their way into the naval base last September

Plymouth Magistrates Court heard that Caerphilly borough councillor Ray Davies, and Dr Margaret Jones, 54, used bolt cutters to enter Devonport naval base in Plymouth in September 2002 to disarm a submarine.

Mr Davies, of Caerphilly, and Dr Jones, of Bristol, both denied a charge of causing criminal damage to four chain link fences belonging to the Ministry of Defence, causing �575.75 damage.

Emma Birt, prosecuting, said the break-in was part of a plan to damage the nuclear powered submarine HMS Tireless, which was undergoing maintenance work at her Devonport home-dock.

There were other avenues open to the defendants to pursue their protest which did not require a criminal offence District Judge David Purcell

It came after a failed attempt by the defendants, who are members of the anti-nuclear protest group Trident Ploughshares, to row up the River Tamar and into the naval base.

After the one-day trial District Judge David Purcell ordered Mr Davies to pay �305.50 compensation and �164 costs.

Previous convictions

He was also given a 12 month conditional charge.

"In this case the defendants' actions clearly amounted to criminal damage," the judge told the defendants.

"There was no intended threat that Trident would be used and there were other avenues open to the defendants to pursue their protest which did not require a criminal offence."