Exiled Congolese opposition leader Moise Katumbi said on Monday he would return to Democratic Republic of Congo by June to lodge his candidacy for a presidential election in December to replace President Joseph Kabila.

The presidential election, originally scheduled for late 2016, has been repeatedly delayed, drawing accusations from the president’s critics that he is trying to cling to power.

Kabila, who has governed Congo since 2001, denies those charges. However, he has refused to rule out trying to change the constitution to remove term limits that bar him from standing for re-election.

“I’m not scared of returning to Congo,” Katumbi told a news conference in Johannesburg.

Katumbi left Congo in May 2016 for medical treatment after being accused by state prosecutors of hiring mercenaries and has been actively courting regional support for his efforts to press Kabila to stand down.

“I will be there to present my candidacy,” Katumbi said, although he declined to give a more precise date.

Returning would expose him to arrest after he was sentenced in June 2016 to three years in prison for real estate fraud. He says the accusations against him are politically motivated.

Failure to hold the election in December could embolden militia groups whose attacks have forced many people to flee their homes, deepening a humanitarian crisis.

The unrest has caused fears that Congo could slide into a new civil war like one that killed millions at the turn of the century.