The Supreme Court of Greece prohibited the participation of the minor far-right Spartans party, which is facing a vote fraud investigation.
The party was not on a list of more than 30 political movements permitted by the court to run in the June 9 vote.
The Supreme Court earlier this month had already prosecuted 11 lawmakers elected with the Spartans for electoral fraud.
Supreme Court prosecutor Georgia Adeilini ordered the move on the grounds that the party is allegedly run by the jailed former spokesman of neo-Nazi party Golden Dawn, Ilias Kasidiaris.
Kasidiaris and a lawyer were also prosecuted for alleged involvement in the scheme.
Greece's electoral court is also examining whether the Spartans should be expelled from parliament altogether.
Shortly before the announcement, a former Spartans lawmaker was held for throwing to the ground an MP from another nationalist party in parliament.
Adeilini had been investigating the case since September after Spartans leader Vasilis Stigkas accused some of his lawmakers of being "guided" by persons "outside parliament."
This was deemed a reference to Kasidiaris, an admirer of the Third Reich who endorsed the Spartans in national elections last June.
They ended up winning more than 240,000 votes and 12 seats in parliament, and Stigkas at the time publicly thanked Kasidiaris for "fuelling" their rise.
The ruling New Democracy party and the PASOK socialists last week filed complaints at the Supreme Court, arguing that Kasidiaris is the "real" leader of the Spartans party.
Several Spartan lawmakers defected from the party after the prosecutions were announced. Stigkas later tried to walk back his statements.
Kasidiaris, 43, is serving a 13-year prison sentence with other leading members of Golden Dawn over crimes including the murder of an anti-fascist rapper.
The hot-tempered former food scientist, who was a lawmaker from 2012 to 2019, has preached to his supporters through voice messages from prison and a YouTube channel that has more than 140,000 followers.
He sparked a major legal wrangle last year when he tried to run for parliament at the head of another newly formed far-right party, Hellenes.
After that failed because of a legal hurdle, he switched his support to the little-known Spartans, who only appeared in opinion polls weeks before the vote.
