Russia’s Central Election Commission (CEC) on Friday upheld its St. Petersburg branch’s decision to bar candidates nominated by the liberal Yabloko party for the upcoming regional parliamentary elections over a technical paperwork issue.

St. Petersburg’s 50-seat legislative assembly, where Yabloko currently holds two seats, is one of eight mostly northwestern Russian regions where Yabloko is fielding candidates in local elections this September.

City election authorities disqualified Yabloko’s entire candidate slate last week on claims a notarized power of attorney lacked explicit language authorizing the party representative to sign financial disclosure paperwork.

Though Yabloko quickly resubmitted corrected notarized documents, St. Petersburg’s election commission rejected the fix, ruling that authority could not be granted retroactively.

On Friday, the CEC voted unanimously to reject Yabloko’s appeal to the St. Petersburg commission’s decision. The party said it plans to appeal that rejection in court.