A member of Greece's Syriza party has claimed that three neo-Nazi Golden Dawn thugs attacked him at a football match at the Olympic stadium in Athens.

Dimitris Stratoulis, of the opposition Coalition of the Radical Left (Syriza), said the three approached him at half-time and beat him several times over the head.

"They approached me and said, 'Stratoulis, we are members of Golden Dawn and we will kill you,'" said the 54-year-old MP, who sustained minor injuries and filed a police complaint after the assault.

Golden Dawn has denied any involvement in the attack. The Neo-Nazi party said in a statement:

"Golden Dawn had nothing to do with the incident against Member of Parliament Stratoulis at the Olympic Stadium. The Leftist party hacks, who promote violence in demonstrations, should stop using the name of the Golden Dawn."

However, Syriza officials directly blamed Golden Dawn for the incident.

"We demand the prompt arrest and prosecution of the perpetrators," the party said in a statement. "It is certain that tolerance towards the fascist Golden Dawn will lead to loss of life. The response must be immediate and decisive before it's too late."

The incident happened after hundreds of people gathered at central Syntagma Square in Athens to protest against the wave of racism and racially motivated attacks on immigrants in Greece.

The rally, organised by the European Grassroots Antiracist Movement (EGAM), was supported by French Nazi-hunter Serge Klarsfeld and Italian Nobel Literature Prize-winner Dario Fo.

"Racism, anti-Semitism and neo-Nazism are developing, in Greece and elsewhere in Europe, without democratic forces responding dynamically and decisively," EGAM said in a statement earlier this month.