The party of Guatemala’s President-elect Bernardo Arévalo was suspended by a government agency on Monday, adding uncertainty to a process marred by legal disputes and accusations of foul play.

The Citizens’ Registry, an office within the country’s electoral authority, provisionally suspended Arévalo’s Semilla party pending an investigation by prosecutors into whether rules were breached during its formation in 2018.

Arévalo later told reporters that Semilla will file an appeal against the decision on Tuesday morning.

The electoral authority on Monday formally confirmed Arévalo as the winner of the Aug. 20 vote, meaning he’s due to take office in January. If the ruling that dissolves his party stands, it would potentially undermine his ability to govern since Semilla legislators might have to sit as independents, making them ineligible for some legislative committees.

Arévalo, 64, remained in contention during the election campaign amid repeated attempts to overturn the result, which led US officials to warn that democracy was under threat in the country. He has pledged to weed out corruption and increase oversight of government spending in the graft-ridden nation.

Arévalo said Monday the ruling will not affect his inauguration on January 14 and said the case is part of an “illegal political persecution led by those who refuse to accept that the people of Guatemala voted for change.”

Irma Pelencia, the head magistrate of the electoral authority, told reporters on Monday that she and her colleagues cannot comment on the registry’s ruling. However, the citizens’ registry is subordinate to electoral authority magistrates, she said.

(Updates with Arévalo’s comments from second paragraph)