Self-proclaimed fascist group Golden Dawn has been found guilty of several crimes by a Greek court at the end of a five-and-a-half year trial.
Thousands of people converged on Greece's main appeals court in Athens on Wednesday ahead of the ruling.
Holding banners - some of which read "Crack down on the Nazis" - a sea of people surrounded the Athens building.
Golden Dawn leader Nikos Mihaloliakos and more than a dozen party members were arrested on charges of founding and participating in a criminal group following the killing of an anti-fascism rapper in 2013 by a party supporter.
The party denied the allegations and says the defendants are victims of a political witch-hunt.
The killing sparked nationwide protests and prompted a government-led crackdown on the fiercely anti-immigrant party, which entered parliament for the first time in 2012 by tapping into voter anger at Greece's economic crisis.
Its anti-austerity and anti-immigrant agenda made it Greece's third-most popular party at the peak of the country's worst financial crisis since World War II. It lost its parliamentary seats in an election last year.
The killing seven years ago of 34-year-old Pavlos Fyssas by a party supporter prompted a crackdown against the party that led prosecutors to arrest and investigate Golden Dawn leaders and politicians over a series of crimes.
"They are not innocent, they must go to jail, they must be convicted," said a 69-year old demonstrator outside the court, who gave her name as Sophia.
"We must send a message to the younger generations, a message against fascism."
