DODOMA, Tanzania (AP) — Tanzania’s president is poised to be declared the winner of Wednesday’s election, while the ruling party appears to have secured the two-thirds majority in parliament required to change the constitution.

Populist President John Magufuli has 83% of votes with 60% of ballots counted, the electoral commission said Friday. The ruling Chama Cha Mapinduzi party has won 194 parliament seats, while opposition parties have won just two. That means upsets even in opposition strongholds, with the leaders of the two main opposition parties losing their seats.

The United States has said “irregularities and the overwhelming margins of victory raise serious doubts about the credibility of the results.” Main opposition presidential candidate Tundu Lissu with the CHADEMA party, who has received 14% of the vote so far, has rejected the election and called for protests.

The opposition alleges widespread fraud including double-voting, ballot box-seizing and the rejection of thousands of election observers from polling stations. Few international observers were allowed to watch the vote.

Observers say Tanzania’s reputation for democratic ideals is crumbling.

An opposition presidential candidate in the semi-autonomous region of Zanzibar was arrested Thursday for the second time this week, then released and told to report to police on Friday. Another ACT Wazalendo official in Zanzibar, Ismail Jussa, was badly beaten by soldiers and hospitalized, the party said.