Malawian President Peter Mutharika plans to challenge a court decision overturning his 2019 poll victory, his spokesman said on Wednesday, in a move that could spark fresh opposition protests.  

After six months of hearings that gripped the southern African country, five top judges on Monday ruled that Mutharika was "not duly elected," citing massive and widespread irregularities including the use of correction fluid on results sheets. The judges ordered a fresh poll within 150 days.  

But Mutharika's spokesman, Mgeme Kalilani, described the ruling as "a serious miscarriage of justice and an attack on the foundations of the country's democracy," telling AFP that Mutharika would appeal. He did not say when Mutharika would bring the challenge, but the 79-year-old president has up to six weeks to appeal.  

On Tuesday, Lazarus Chakwera, the leader of the main opposition Malawi Congress Party, who came a close second to Mutharika, hailed the landmark verdict as a victory for democracy and Africa. 

Addressing more than 10,000 jubilant opposition supporters who thronged his party's Lilongwe headquarters, Chakwera said "this is a great day."  

"It is democracy that has won. It is Malawi that has won. It is Africa that has won. And now justice has been served," he said.  

Mutharika was declared the winner of the May 21 election with 38.5 percent of the vote, Chakwera losing by just 159,000 votes. Chakwera went to court to challenge the result.  

In their unprecedented ruling, the constitutional court judges concurred that "the irregularities and anomalies have been so widespread, systematic and grave... that the integrity of the results has been seriously compromised."  

The court said only 23 percent of the result sheets had been able to be verified, and that the outcome announced by the electoral commission "cannot be trusted as a true reflection of the will of the voters."  

It is the first time a presidential election has been challenged on legal grounds in Malawi since independence from Britain in 1964, and only the second African vote result to be canceled, after the 2017 Kenya presidential vote.