A group of US senators say they will refuse to certify Joe Biden’s election victory unless a commission is set up to investigate alleged voter fraud.
The 11 senators and senators-elect, led by Ted Cruz, want a 10-day delay to audit the unsubstantiated allegations.
The move is not expected to succeed as most senators are expected to endorse Mr Biden in the 6 January vote.
President Donald Trump has refused to concede, repeatedly alleging fraud without providing any evidence.
His legal efforts to overturn results have been rejected by the courts.
The US Electoral College – which confirmed November’s presidential election result by awarding points for each state won by the two White House rivals – last month cemented Mr Biden’s victory over Mr Trump by 306-232.
These votes must be affirmed by Congress on 6 January. Inauguration Day, when the new Democratic president and vice-president are sworn in, will be on 20 January.
What do Trump allies want?
In a statement, the 11 senators led by Texas senator Ted Cruz said November’s election had “featured unprecedented allegations of voter fraud, violations and lax enforcement of election law, and other voting irregularities”.
Citing a precedent from 1877 – when a bi-partisan committee was formed to investigate after both parties claimed victory in three states – they urged Congress to appoint a commission for an “emergency 10-day audit of election returns in the disputed states”.
“Once completed, individual states would evaluate the commission’s findings and could convene a special legislative session to certify a change in their vote, if needed,” they said.
However they said their bid was unlikely to succeed. “We are not naïve. We fully expect most if not all Democrats, and perhaps more than a few Republicans, to vote otherwise,” they said.
Their move is separate from that of Missouri Senator Josh Hawley, who has also said he will reject the Electoral College result over election integrity concerns.
A group of Republicans in the lower chamber of Congress, the House of Representatives, is also planning to contest the election results.
What will happen on 6 January?
Electoral count 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.
But for electoral votes to be rejected, a majority in both chambers must uphold the objection. This scenario is seen as all but impossible since Democrats hold a majority in the House and some Republicans in the Senate have already said they will not contest the results.
Top Republicans have said the Senate’s role in certifying the election is largely ceremonial and should not be an opportunity for further lengthy debate about the result.
Senate majority leader Mitch McConnell has already recognised Mr Biden’s victory and has asked other Republicans not to object.
The decision by some Republicans to defy their leadership indicates a growing split within the party, the BBC’s Washington correspondent Lebo Diseko says.
The Biden camp has not responded to the latest move to object to the election result. But Biden spokeswoman Jen Psaki has described Mr Hawley’s attempt as “antics”.
“The American people spoke resoundingly in this election and 81 million people have voted for Joe Biden and Kamala Harris,” she said.
“Congress will certify the results of the election as they do every four years.”
With at least a dozen Republican senators now planning to challenge the election results in Congress, it is clear – if it wasn’t already – that the party’s heart continues to be with Donald Trump’s efforts to overturn his presidential loss.
The effort will be futile, given the Democratic majority in the House of Representatives, but the goal for many of these politicians is not to pull off a miraculous reversal of fortune for the president. Instead, it is to curry favour with Trump’s loyal base.
They are wagering that the road to success in the Republican Party will continue to run through Trump and his faithful, whos support could be invaluable to senators with presidential ambitions, like Ted Cruz of Texas or Josh Hawley of Missouri, or ones concerned about future primary opposition from pro-Trump politicians.
This is not the first time members of Congress dismayed by the outcome of a presidential election have objected during the largely ceremonial counting of Electoral College votes. It will, however, be the largest such revolt in nearly a century and a half.
It is a sign that the partisan rancour in the US, exacerbated by Trump’s scorched-earth fight to hold on to the presidency, will not fade away anytime soon.