Zimbabwe’s Movement for Democratic Change (MDC) has filed a legal challenge to Robert Mugabe’s victory in last week’s presidential elections.
The electoral petition seeks an order for the result to be declared null and void and a new election to be called within 60 days.
The MDC’s 15 grounds include alleged bribery, abuse of “assisted voting” and manipulation of the electoral roll.
Mr Mugabe, 89, won with 61% of the presidential vote.
His Zanu-PF party gained a parliamentary majority of more than two-thirds, with 160 seats against 49 for the MDC.
The MDC is to file a complaint on the parliamentary results at a later date, reports the BBC’s Brian Hungwe in the capital Harare.
With a two-thirds majority, Zanu-PF is able to amend the constitution, potentially restoring presidential powers which were reduced earlier this year.