Emmerson Mnangagwa’s inauguration as Zimbabwe’s president has been postponed after the main opposition party filed a legal challenge to the results of last month’s election.

Justice minister Ziyambi Ziyambi announced a ceremony planned for Sunday “will no longer happen” after the Movement for Democratic Change (MDC) alleged irregularities in the country’s first vote since long-serving leader Robert Mugabe was deposed.

The opposition party has demanded either fresh elections or the instalment of their candidate, Nelson Chamisa, as president.

The MDC’s lawyers arrived at court on Friday to submit papers less than an hour before the seven-day deadline to challenge the result.

“We have a good case and cause,” declared Mr Chamisa on Twitter.

Zimbabwe’s Electoral Commission has said President Mnangagwa and his ruling Zanu-PF party won the 30 July election, with the president receiving 50.8 per cent of the vote and Mr Chamisa polling 44.3 per cent.

The vote was Zimbabwe’s first without Mr Mugabe on the ballot, after a coup in November ended his 30-year rule as president.

There had been hopes the end of Mr Mugabe’s presidency would begin a new era for the country after decades of political and economic paralysis.

Mr Mnangagwa, a close ally of Mr Mugabe who later took part in his ousting, has said he wants to make Zimbabwe more open and democratic.

But Zimbabwe has been rocked by violence since following the bitterly disputed election, with opposition supporters harassed and beaten in the streets.

Two days after the election, soldiers opened fire during opposition protests in the capital, Harare, killing six people.

Foreign governments, Western election observers and human rights activists have expressed concern about the “excessive” force and the reports of opposition supporters being targeted by security forces.

The MDC claimed soon after the election that the vote was rigged but withheld evidence for the court challenge.

“We have managed to place before the courts all the mathematical and statistical irregularities,” party lawyer Thabani Mpofu told journalists as after emerging from court. A copy of the filing was not immediately available.

A number of grassroots groups and NGOs that fanned out across the country have released reports questioning high turnout in some areas and highlighting striking differences in the number of voters for the presidential and parliamentary elections.

On Thursday, senior opposition figure Tendai Biti was charged with inciting public violence and declaring unofficial election results as fears grew over a government crackdown. Mr Biti had alleged before the electoral commission’s official announcement that Mr Chamisa was the real winner.

Mr Biti first fled to Zambia, where authorities denied asylum and handed him over to Zimbabwean security forces in defiance of a Zambian court order. The United States and several other nations, as well as the UN refugee agency, have expressed concern.

In pictures: Zimbabwe votes in historic election Show all 55 1 /55 In pictures: Zimbabwe votes in historic election In pictures: Zimbabwe votes in historic election People in Mbare celebrate after officials announced the re-election of President Emmerson Mnangagwa Getty Images In pictures: Zimbabwe votes in historic election Supporters celebrate at the Harare International Convention Centre in the early hours Getty Images In pictures: Zimbabwe votes in historic election People in Mbare celebrate Getty Images In pictures: Zimbabwe votes in historic election People in Mbare celebrate Getty In pictures: Zimbabwe votes in historic election Supporters sing and dance soon after the announcement EPA In pictures: Zimbabwe votes in historic election Supporters sing and dance soon after the results of the Presidential elections were announced at the Harare International Convention Centre EPA In pictures: Zimbabwe votes in historic election A vendor sells sponges near newspaper headlines on the streets of Harare AP In pictures: Zimbabwe votes in historic election Supporters of the newly reelected Zimbabwe President Emmerson Mnangagwa celebrate in Mbare AFP/Getty Images In pictures: Zimbabwe votes in historic election People in Mbare celebrate Getty Images In pictures: Zimbabwe votes in historic election A man reads a Zimbabwean newspaper the day after the violence on the streets of Harare EPA In pictures: Zimbabwe votes in historic election A soldier fires shots towards demonstrators AFP/Getty Images In pictures: Zimbabwe votes in historic election A wounded man reacts at the sight of soldiers while taking shelter in a stall at a market in Harare AFP/Getty Images In pictures: Zimbabwe votes in historic election Supporters of the opposition Movement for Democratic Change party (MDC) light a fire in the streets of Harare. Reuters In pictures: Zimbabwe votes in historic election Soldiers open fire to disperse crowds of the opposition Movement for Democratic Change supporters outside the party's headquarters in Harare REUTERS In pictures: Zimbabwe votes in historic election Opposition MDC party supporters hold a voting placard up high on a street in Harare AP In pictures: Zimbabwe votes in historic election A supporter of Zimbabwean opposition MDC Alliance allegedly beaten up by soldiers sits with blood on his face as other protesters assist him AFP/Getty Images In pictures: Zimbabwe votes in historic election A vendor scurries for cover with her wares as soldiers disperse demonstrators AFP/Getty Images In pictures: Zimbabwe votes in historic election A wounded man hides under a tarpauling while the Zimbabwean Army patrols the streets of Harare AFP/Getty Images In pictures: Zimbabwe votes in historic election Anti-riot police officers close the entrance to the Rainbow Towers, where the election results were announced in Harare Getty In pictures: Zimbabwe votes in historic election Soldiers open fire on citizens REUTERS In pictures: Zimbabwe votes in historic election Citizens run the Zimbabwean army during protests in Harare Reuters In pictures: Zimbabwe votes in historic election Supporters of the opposition Movement for Democratic Change party (MDC) protest the result of the election, which they allege to be fraudulent Getty In pictures: Zimbabwe votes in historic election Supporters of the opposition protest in the streets of Harare as police fire tear gas AP In pictures: Zimbabwe votes in historic election A soldier assaults a man on the streets of Harare during protests AP In pictures: Zimbabwe votes in historic election Zimbabwean anti riot police officers sit in a truck amidst protesters on the streets of Harare Getty In pictures: Zimbabwe votes in historic election Citizens run from riot police amidst protests in Harare AP In pictures: Zimbabwe votes in historic election Soldiers patrol the streets during protests in Harare Reuters In pictures: Zimbabwe votes in historic election A Zimbabwean soldier beats a man on the streets of Harare Getty In pictures: Zimbabwe votes in historic election A man lies dead after the Zimbabwean army shot at protesters in Harare Getty In pictures: Zimbabwe votes in historic election A supporter of the opposition party protests in the streets of Harare Reuters In pictures: Zimbabwe votes in historic election Zimbabwean soldiers beats an opposition supporter on the streets of Harare Reuters In pictures: Zimbabwe votes in historic election Supporters of the opposition protest in the streets of Harare AP In pictures: Zimbabwe votes in historic election Supporters of the opposition protest in the streets of Harare as police fire tear gas Getty In pictures: Zimbabwe votes in historic election Supporters of the opposition burn a campaign banner of the ruling Zanu-PF party Reuters In pictures: Zimbabwe votes in historic election A man casts his vote in Mbare, a suburb of Zimbabwean capital Harare Getty In pictures: Zimbabwe votes in historic election A police officer keeps watch of queuing voters in Mbare Getty In pictures: Zimbabwe votes in historic election Voters stand in line outside a polling station in Mbare Getty In pictures: Zimbabwe votes in historic election Election officials remove political posters near a polling station on voting day Getty In pictures: Zimbabwe votes in historic election Oppostion leader Nelson Chamisa arrives at a polling station in Harare Getty In pictures: Zimbabwe votes in historic election Oppostion leader Nelson Chamisa casts his vote AP In pictures: Zimbabwe votes in historic election Zimbabwean president Emmerson Mnangagwa arrives to cast his vote in Kwekwe Reuters In pictures: Zimbabwe votes in historic election Zimbabwean president Emmerson Mnangagwa casts his vote AP In pictures: Zimbabwe votes in historic election Voters stand in line outside a polling station in Kwekwe AP In pictures: Zimbabwe votes in historic election A woman prays outside a polling station in Mbare Getty In pictures: Zimbabwe votes in historic election Voters arrive at a polling station in Harare EPA In pictures: Zimbabwe votes in historic election Former president Robert Mugabe prepares to cast his vote in Harare AP In pictures: Zimbabwe votes in historic election A woman casts her vote in Mbare, a suburb of capital Harare Getty In pictures: Zimbabwe votes in historic election A woman casts her vote in the township of Makokoba Getty In pictures: Zimbabwe votes in historic election A police officer casts his vote in Mbare Getty In pictures: Zimbabwe votes in historic election A woman prays near a polling station in Mbare EPA In pictures: Zimbabwe votes in historic election A man casts his vote in Harare AP In pictures: Zimbabwe votes in historic election Former president Robert Mugabe speaks at a press conference the day before the vote where he stated that he would not be voting for his former Zanu-PF party Reuters In pictures: Zimbabwe votes in historic election A supporter of the opposition MDC party attends the final campaign rally in Harare on July 28 Reuters In pictures: Zimbabwe votes in historic election Supporters of the opposition MDC (Movement for Democratic Change) party attends the final campaign rally in Harare on July 28 EPA In pictures: Zimbabwe votes in historic election Supporters of the opposition MDC (Movement for Democratic Change) party attends the final campaign rally in Harare on July 28 EPA

Zimbabwe’s Constitutional Court has 14 days to rule on the challenge to the election result.

Judges can declare a new winner or order a fresh election. But some opposition leaders have expressed scepticism about whether the courts will fairly assess the election challenge, warning they are biased towards the government.

However, Mr Mpofu said the MDC ”wouldn’t have come to court if we thought that the court would not give us a fair hearing”.

He added: “On the basis of the evidence we have placed before the court, we seek in the main relief to the effect that the court should declare the proper winner and the proper winner is my client.