LILONGWE, Malawi — Malawi’s Constitutional Court on Monday annulled the May 2019 presidential election that declared Peter Mutharika a winner and ordered a rerun, after opposition parties cited evidence of widespread irregularities.

Mr. Mutharika, Malawi’s president since 2014, won the election with a reported 38.57 percent share of the vote. Opposition party leader Lazarus Chakwera received 35.41 percent and Deputy President Saulos Chilima, who formed his own party, had 20.24 percent in the final tally.

The electoral commission declared Mr. Mutharika the winner despite complaints of irregularities, including results sheets with sections blotted out or altered with correction fluid.

Mr. Mutharika had pledged to crack down on corruption and revive the economy in his second five-year term.