Which Democrats have called on Biden to end his presidential campaign?

A growing number of Democrats in the U.S. Congress are calling on Democratic President Joe Biden to end his re-election bid after the 81-year-old incumbent's halting debate performance against Republican rival Donald Trump.

While many lawmakers have expressed unease with Biden's continued candidacy - and others have steadfastly backed the incumbent's plans - here is a list of those who have publicly and directly called for Biden to not run again.

Representative Adam Smith

"President Biden should end his candidacy for a second term as President and release his delegates to the Democratic National Convention to enable the party to nominate a new candidate for President," Smith said in a statement. "The President’s performance in the debate was alarming to watch and the American people have made it clear they no longer see him as a credible candidate to serve four more years as President. Since the debate the President has not seriously addressed these concerns. This is unacceptable. The stakes are simply too high."

Representative Lloyd Doggett

Doggett, a U.S. House of Representatives member from a safe Democratic district in Texas, was the first congressional Democrat to call for Biden to step down.

"President Biden has continued to run substantially behind Democratic senators in key states and in most polls has trailed Donald Trump," Doggett said in a statement. "I had hoped that the debate would provide some momentum to change that. It did not."

Representative Raul Grijalva

Grijalva, a liberal who represents a district in southern Arizona along the border with Mexico, told the New York Times it was time for Biden to end his campaign, saying, "If he's the candidate, I'm going to support him, but I think that this is an opportunity to look elsewhere." Grijalva representatives did not respond to requests for comment.

Representative Seth Moulton

Moulton, a Democrat from Massachusetts, praised Biden's service to the country but told a local radio show that the president should follow in "George Washington's footsteps and step aside to let new leaders rise up and run against Donald Trump."

Representative Mike Quigley

A moderate from Illinois, Quigley told MSNBC that Biden must step aside and "let someone else do this" or risk "utter catastrophe."

Representative Angie Craig

Craig, whose district in Minnesota is considered a top priority for Republicans to win back in November, was the first incumbent from a highly competitive district to call for Biden to step down.

"Given what I saw and heard from the president during last week's debate in Atlanta, coupled with the lack of a forceful response from the president himself following that debate, I do not believe that the president can effectively campaign and win against Donald Trump," Craig said.