Vice President Mike Pence said on Wednesday that he lacked constitutional authority to follow President Trump's wishes to throw out Electoral College votes for President-elect Joe Biden.

Why it matters: Trump has been pressuring Pence to overturn the election results as part of an ongoing attempt to subvert Biden's clear win, which failed to garner evidence or support through various legal battles. Trump will view Pence’s statement as the ultimate act of betrayal.

What they're saying: "It is my considered judgement that my oath to support and defend the Constitution constrains me from claiming unilateral authority to determine which electoral votes should be counted and which should not," Pence wrote.

• Pence rejected the notion that he "should be able to accept or reject electoral votes unilaterally" — after Trump insisted he was able to do exactly that — and also pushed back against the idea that "electoral votes should never be challenged" by Congress.
• Trump addressed loyal supporters outside the White House as Pence released his statement, and called on Pence to do "the right thing" as he presides over Congress in a largely ceremonial capacity on Wednesday.

In response to Pence's refusal to overturn the election results, Trump tweeted: "Mike Pence didn’t have the courage to do what should have been done to protect our Country and our Constitution, giving States a chance to certify a corrected set of facts, not the fraudulent or inaccurate ones which they were asked to previously certify. USA demands the truth!"

The state of play: As expected, Republicans objected to certifying the Electoral College count on Wednesday.

Read Pence's letter:

This is a breaking news story and will be updated.