US lawmakers have gathered for what could be a volatile session to confirm Joe Biden as president, with Donald Trump’s supporters also gathered to protest against the election result.
A joint session of Congress is counting and confirming electoral college votes.
The proceedings are usually brief and ceremonial but Republican lawmakers have now objected to some results, triggering a lengthy debate and vote.
But any attempts to block Mr Biden’s victory are almost certain to fail.
For days Mr Trump has also been putting pressure on Vice-President Mike Pence, who is presiding over the session, to block certification of the result.
But in a letter to Congress on Wednesday, Mr Pence said that he had no “unilateral authority to decide which electoral votes should be counted”.
Nevertheless, Mr Trump is making a final stand against the certification of his defeat.
Thousands gathered in Washington DC for a “Save America Rally”, with Mr Trump addressing them. He urged them to march to the Capitol building to support those legislators opposing Mr Biden’s confirmation.
Hundreds of National Guard members and police officers have been mobilised in case there is trouble between opposing protesters.
Mr Trump has refused to concede the 3 November election, repeatedly alleging fraud without providing any evidence.
On Wednesday, he said again: “We will never give up. We will never concede.”
He has also tried to throw doubt on the integrity of Tuesday’s Senate run-off votes in the southern, traditionally Republican, state of Georgia. Projections by US TV networks suggest the Democrats have won one of the seats and are neck-and-neck for the second seat.
If the Democrats win both they will gain effective control of the Senate – something that will help Mr Biden push forward his agenda after he is inaugurated as president on 20 January.
What will happen in Congress?
The two houses of Congress – the House of Representatives and the Senate – will hold a joint session on Wednesday, where they will open sealed certificates from the 50 US states containing a record of their electoral votes.
Under the US system, voters cast their ballots for “electors”, who in turn formally vote for the candidates weeks after the election. Mr Biden received 306 votes under the electoral college system, to Mr Trump’s 232.
The proceedings are scheduled to begin at 13:00 local time (1800 GMT).
Bipartisan representatives from the two chambers will read out the results on Wednesday and do an official count.
There is a split in the Republican party, with dozens of House Republicans and a smaller group of Senators expected to object to the count from some of the key swing states.
Ted Cruz is leading a group of about a dozen senators calling for a 10-day delay to audit unsubstantiated allegations of election fraud.
Mr Pence – who as president of the Senate is due to declare Mr Biden the winner – earlier said he welcomed this move.
He stopped short of repeating allegations of fraud but his chief of staff said Mr Pence shared what he called “the concerns of millions of Americans about voter fraud and irregularities”.https://emp.bbc.com/emp/SMPj/2.36.7/iframe.htmlmedia captionTrump: “If [Pence] doesn’t come through, I won’t like him quite as much”
Objections that are endorsed by a member of the House of Representatives and a member of the Senate must be considered by lawmakers in a two-hour debate, followed by a vote.
However, for an objection to be upheld, a majority in both chambers must vote in favour. Republicans hold the majority in the Senate but some of their members have already said they will not contest the results. Democrats are in the majority in the House.
Senate Majority Leader Mitch McConnell has already recognised Mr Biden’s victory and asked other Republicans not to object.
What about the protests?
Thousands of supporters of Mr Trump have joined the rallies in Washington, with Mr Trump addressing them near the White House on Wednesday.
He repeated unsubstantiated claims of election fraud and also turned on “weak Republicans” who had failed to support his allegations.
Officials had warned Trump supporters not to carry guns.
Police on Monday arrested the leader of the far-right Proud Boys, charging him with destruction of property related to a previous protest. Enrique Tarrio was later released but a judge ordered him to stay out of Washington.
Mr Tarrio has said on the social media app Parler that the Proud Boys will “turn out in record numbers”.
The National Guard has been asked by Washington DC’s mayor to help with crowd management and traffic control.