Greek parties and unions on Wednesday were to hold anti-fascist protests in Athens and other cities as police stepped up an investigation into suspected crimes by aggressive neo-Nazi party Golden Dawn.
Most of the country's mainstream parties called for a large turn-out in the early evening protests, which were sparked by the murder of an anti-fascist musician, allegedly at the hands of a self-confessed neo-Nazi last week.
"We call all institutional and social institutions to mobilise," said the socialist Pasok party, a member of the government coalition, while the main opposition Syriza leftists called for a "peaceful march in defence of democracy."
The fatal stabbing on September 18 of 34-year-old musician Pavlos Fyssas by unemployed truck driver George Roupakias, who admitted the crime but said he was acting in self-defence, has prompted an unprecedented crackdown on Golden Dawn after months of inaction by the authorities.
In recent months, Golden Dawn has been accused of instigating beatings against migrants and political opponents, and several of its lawmakers have been implicated in assaults, but police had failed to pursue most of the cases.
This changed after Fyssas' murder, with the government this week suspending several senior police officers for failing to investigate suspected illegal activity by Golden Dawn.
Police raids on Golden Dawn offices in search of hidden weapons were also ordered this week, amid reports that the party organised military-style training activities for its members.
On Tuesday, a police officer assigned to a Golden Dawn lawmaker prosecuted for anti-migrant aggression was arrested in the central town of Agrinio.
Golden Dawn has vehemently denied links to Fyssas' killer, despite pictures emerging of him participating in party activities, and says it is the victim of a smear campaign.
Capitalising on a rise in social tension in the debt-stricken country, Golden Dawn was first elected to parliament last year with nearly seven percent of the vote, winning 18 seats out of an overall 300.
Until Fyssas' murder, its approval ratings had steadily grown and it was the third most popular party in the country.