He added: “Violence is a downhill slide that destroys any chance of Greece achieving what it deserves, in other words growth, prospects and prosperity.”

Socialist Pasok party leader Evangelos Venizelo said the Golden Dawn must be treated as a criminal organisation.

A wave of anti-fascist protests has gripped several cities in the wake of the stabbing in the early morning hours of Wednesday.

Candles and flowers have been laid on the spot near the Athens suburb of Keratsini where 34-year old Pavlos Fyssas bled from the two knife wounds in his chest.

Fyssas, along with his friends, had been chased out of a cafe and pursued by black-clad members of the Golden Dawn just after midnight on Tuesday.

He identified the alleged culprit before passing away.

Thousands gathered at his memorial on Wednesday with youths later in the evening setting fire to bins to protest the killing.

Media reports say some threw stones at police who returned fired with tear gas to disperse the demonstrators, ending with 23 arrests.

Fyssas’ body was buried at a cemetery in Athens on Thursday with a reported 2,000 people attending the funeral.

The Council of Europe (CoE) - a human rights watchdog in Strasbourg - has also condemned the killing and expressed its support into a government-led investigation into Golden Dawn’s involvement.

“This murder stems from an extremely dangerous development we are seeing in Greece and also other parts of Europe. Sections of society are becoming more radicalised and there is a real risk that hate speech turns into violence and cold-blooded murder,” said Secretary General Thorbjorn Jagland.

The council’s top human rights commissioner, Nils Muiznieks, in April had already called upon the group to be outlawed.

Muiznieks said the group is responsible for numerous crimes. He noted that a few days before his arrival in Greece, a migrant with severe wounds had the Greek Golden Dawn initials "XA" cut into his back.

Another was knifed to death. One of the assailants was a Golden Dawn member.