Zimbabwe’s MDC opposition party on Wednesday confirmed it would launch a legal challenge to President Emmerson Mnangagwa’s narrow election victory, which it says was due to fraud.

“Those results represent a total negation of the will of the people,” MDC lawyer Thabani Mpofu told reporters. “The election results made by ZEC (Zimbabwe Electoral Commission) will be challenged.”

Mpofu declined to give the date when the legal case will be lodged, which is set to delay Mnangagwa’s inauguration.

Under Zimbabwean law, the deadline for filing the challenge is Friday. The Constitutional Court must rule on the petition within 14 days.

“Evidence derives from ZEC’s figures that in our view grossly mathematically fail to tally,” said Mpofu.

“We have what we require for the purposes not just of mounting a credible and sustainable challenge, but that will yield a vacation of the entire process announced by ZEC.

“We are convinced once this has been placed before a court, there will only be one outcome.”

The MDC headquarters were raided by authorities in what Mpofu described as “an attempt to destroy our evidence”, but he said their data was “secure”.

He gave no details about the evidence of alleged fraud, promising to reveal “a secret weapon” in court.

Mnangagwa, a former ally of ousted Robert Mugabe, narrowly retained power in last week’s landmark vote, but the MDC has repeatedly said it actually won.

The president, the ruling ZANU-PF party and the electoral commission have dismissed charges of cheating.