Lieberman, a former U.S. senator and unsuccessful vice presidential candidate, said No Labels hopes to offer a legitimate "third choice" candidate.
"We're not in this to be spoilers," Lieberman told ABC's "This Week" program.
Former Democratic Senator Doug Jones said a third-party No Labels candidate could not secure the 270 Electoral College votes needed to win.
But he said a No Labels candidate could help Trump regain the White House he lost to Biden in 2020.
Republican presidential candidate Chris Christie rejected the group's approach outright on Sunday.
Persons:
Joe Lieberman, Lieberman, We're, ABC's, we're, John Hope Bryant, Benjamin Chavis Jr, Larry Hogan, Pat McCrory, Joe Manchin, Joe Biden, Donald Trump, Ross Perot, Bill Clinton, Ralph Nader, George W, Bush, Doug Jones, Trump, Jones, Chris Christie, Al Gore's, David Morgan, Howard Goller
Organizations:
Democratic, Republican, North Carolina, Democrats, Former Democratic, Electoral, Biden, ABC, U.S . Capitol, New, Senate, Thomson
Locations:
U.S, New Hampshire, New Jersey