The far-right party of Brazil's outgoing president, Jair Bolsonaro, has challenged some votes in October's election that saw him lose narrowly to leftist Luiz Inacio Lula da Silva.
The Liberal Party asked the electoral court to reject ballots from certain voting machines, which it claims were compromised during the second round.
The court has now given the party 24 hours to amend its petition, to include the first round of voting.
The same machines were used both times.
Mr. Bolsonaro's party performed better than expected in the first round. The party has not presented proof for its allegation of machine errors.
Lula's victory - with 50.9% to Mr. Bolsonaro's 49.1% - has been ratified by the Superior Electoral Court (TSE), so the challenge may not get very far.
It concerns some 280,000 voting machines which were models deployed before 2020. Mr. Bolsonaro has previously claimed that Brazil's electronic voting system is not fraud-proof.
Mr. Bolsonaro, while not conceding defeat, has given the go-ahead for a presidential transition. He has stepped away from the public gaze since losing the election on 30 October.
According to his party, if the votes in question were discounted, he would win re-election "with 51.05% of the valid votes, against 48.95% for Lula".Immediately after Lula's win was declared many lorry drivers supporting Mr. Bolsonaro erected roadblocks and there were scuffles with police. But Mr. Bolsonaro later told them that blocking roads was not a part of "legitimate" protests.
Some of his followers have continued demonstrating outside military barracks, urging a military intervention to prevent Lula from taking office. Mr. Bolsonaro's term as president will end when Lula is inaugurated on 1 January.
Lula, who previously served as president from 2003 to 2010, is now 77 and will become the oldest person to assume the post.
Lula's victory was a stunning comeback for a politician who could not run in the last presidential election in 2018 because he was in jail and barred from public office. He had been found guilty of receiving a bribe from a Brazilian construction firm in return for contracts with Brazil's state oil company Petrobras. His conviction was later annulled.
Mr. Bolsonaro, a former army captain, drew much support from evangelical Christians and other conservatives anxious to protect family values. But his tenure also saw accelerated deforestation of the Amazon and growing inequality.
source(BBC)