"I just filed a petition a few minutes ago before the Constitutional Court in Karlsruhe to have the NPD's conformity to the constitution recognised," said National Democratic Party of Germany head Holger Apfel in a video posted Tuesday on the party website.
A court spokesman confirmed to news agency AFP that the petition had been filed, while Apfel said that if it were rejected he would be ready to turn to the European Court of Human Rights.
In March, Germany's regional interior ministers announced that they would try to assemble a case towards getting the NPD banned. Having given themselves half a year to gather evidence, they are not expected to file a formal request until next month.
In November of last year, a poll showed that three-quarters of Germans wanted a ban on the NPD, in a survey that followed the discovery of an extreme far-right cell believed to have murdered 10 people, mainly Turkish shopkeepers.
Last week, German prosecutors said they brought murder charges against 37-year-old Beate Zschäpe, who is said to have been at the heart of the neo-Nazi cell accused of the seven-year killing spree.
In existence since 1964, the NPD won 1.5 percent of the vote at the last national elections in 2009.
In 2003, a first attempt to ban the NPD failed, when the Constitutional Court - the only court able to make such a pronouncement - argued that the presence of undercover intelligence officers in the party posed a legal complication.