The Scottish Socialist MSP, Rosie Kane, has been ordered to do community service after an anti-nuclear demonstration at Faslane naval base on the Clyde.
Rosie Kane outside court in Helensburgh
She was convicted of a breach of the peace by blocking traffic during a blockade at the base in October 2001.
Kane, who was one of six SSP MSPs elected to the parliament in May, was fined £150 but told Argyll and Bute District Court she had no intention of paying.
An alternative sentence of 20 hours community service was imposed.
Kane, 42, had denied committing an offence by lying down and refusing to move during the demonstration against the UK's Trident submarine fleet.
She told Justice of the Peace Vivien Dance: "I'm not guilty of a crime, I'm not a danger to society, in fact I was struggling against a danger to society."
'Waste of time and money'
Outside court Kane, a list member for Glasgow, said she was prepared to go to prison for her beliefs but was pleased Mrs Dance had imposed community service as an alternative rather than a jail term.
The MSP said: "I thought I would have to pay a fine or be banged up but I think Mrs Dance listened to me and thought about it, you get the feeling that she understood.
"This is all a waste of time and a waste of money. It's the third time I have been up in court for protesting and I will be up again."
Kane said she was not deterred by her court appearance or the fine and would be taking part in the next anti-nuclear protest at the Faslane base.