Members of Greece's far right Golden Dawn party handed out free food to hundreds of people on Syntagma Square on Wednesday.
The food was only made available to Greeks.
Organizers asked for the ID cards of people queuing for food to check if they were Greek citizens. They said that unemployed persons and people with many children would be served first.
More than two hundred people turned up, according to witnesses.
Golden Dawn spokesman Ilias Kasidiaris said the food -- potatoes, pasta, milk and olive oil -- came from Greek firms and Greek producers exclusively.
The campaign took place despite a ban from local authorities which on Tuesday refused to give permission for the event. In a letter sent to the party, the Athens municipality said Syntagma Square cannot be made available for this type of events.
Golden Dawn was advised to use a square in the capital's Gazi district instead.
“Athens mayor Giorgos Kaminis does not mind when illegal immigrants and anarchists use the square,” a member of the party who did not identify himself said.
Golden Dawn won 7 percent of the vote in Greece's recent elections on the back of rising anti-immigrant sentiment.
A recent drive by the party to get Greeks to donate blood only for their fellow citizens was blocked by doctors and medical authorities who slammed the initiative as racist and inhuman.