ATHENS — A far-right party banned from participating in Greece’s upcoming election pledged support Friday for a newly founded political group that received Supreme Court approval to field candidates.

It was the latest twist in Greece’s volatile far-right politics that could have an impact on the upcoming election.

Greece’s top court this week upheld an earlier election ban on the Greeks Party. The ruling was based on recently approved legislation that denies political groups tied to serious offenses or opposed to the democratic nature of the constitution the right to put up candidates.

The party’s founder, former Greek lawmaker Ilias Kasidiaris, 42, is serving a prison sentence of 13 years and six months for membership in a criminal organization. He is a former leading member of Golden Dawn, a party of neo-Nazi origins linked to multiple violent street attacks.

Kasidiaris said Friday that he would support the little-known Spartans Party in the June 25 elections for Greece’s parliament.

During elections held last month, the head of Greece’s conservative New Democracy party, Kyriakos Mitsotakis, narrowly missed winning the right to continue governing the country as prime minister. But Mitsotakis stands to benefit from a change in how parliament seats are allocated that takes effect in this month’s voting.

Opinion polls indicate that Mitsotakis holds a 20-point lead over main rival Alexis Tsipras, a former prime minister who leads the left-wing Syriza party.

Several far-right parties are vying for national representation in parliament, with the threshold set at 3% of the national vote.