Trump, White House officials and Republicans on Capitol Hill have seized on the absence of such a vote as an unacceptable break with House precedent and have vowed to resist what they describe as an illegitimate probe.

But Democrats defended their current impeachment process, which has multiple House committees interviewing witnesses in private and gathering evidence related to allegations that Trump and his personal lawyer, Rudy Giuliani, pressured Ukrainian officials to begin an investigation into former Vice President Joe Biden and his son — potentially at the risk of losing U.S. military aid.

"There's no requirement that we have a vote, and at this time, we will not have a vote," Pelosi told reporters Tuesday evening.

"We're not here to call bluffs. We're here to find the truth, to uphold the Constitution of the United States," Pelosi added. "This is not a game for us, this is deadly serious."

House Majority Leader Steny Hoyer (D-Md.) told reporters, “The processes that are being pursued are consistent with the Constitution and the law, and by the way, Republican rules.”

Yet Pelosi and other top Democrats couldn't come to an agreement among themselves during internal discussions on Tuesday over whether to move forward with the vote, which would mark an escalation of their impeachment battle with Trump. Vulnerable House Democrats from swing districts were also largely opposed, with some lawmakers fearing that the American public would confuse a vote authorizing an impeachment inquiry as actually impeaching Trump.

Inside the leadership, Hoyer and House Majority Whip Jim Clyburn (D-S.C.). were opposed to the vote, as were Judiciary Committee Chairman Jerry Nadler (D-N.Y.) and Intelligence Committee Chairman Adam Schiff (D-Calif.), two key players in the impeachment drama, said several Democratic aides.

Pelosi privately told other Democrats she was "agnostic" on the issue, said a Democratic aide.

During Tuesday's meeting, Pelosi told her colleagues that she "only has license this caucus gives me," meaning she wouldn't pressure her rank-and-file to hold the vote.

House Democratic leaders also quietly reached out to the most vulnerable members of their caucus to gauge whether they would support a formal vote to authorize an impeachment inquiry against Trump, according to multiple Democratic aides.

The response was "pretty strongly no," said an aide close to the issue. The idea has met with anxiety among some of the battleground Democrats, who fear it could distract from the rest of their agenda, according to multiple aides.

Several “Frontliners” in key districts raised concerns as well, including freshman Reps. Anthony Brindisi (D-N.Y.), Abigail Spanberger (D-Va.), Chrissy Houlahan (D-Pa.) and Elissa Slotkin (D-Mich.).

Brindisi pointed out that there's no constitutional requirement for such a vote, while pointing out that he hadn't backed an impeachment inquiry publicly yet. Just six other Democrats have yet to endorse the inquiry.

"You said it perfectly," Pelosi responded.

Houlahan asked if Democrats "were being fair" to Republicans, while Spanberger urged members to talk about anything other than impeachment while they're on TV.

But holding an impeachment inquiry vote would undermine a key Republican talking point — that Democrats’ inquiry isn’t valid because they haven’t held a floor vote, as in past presidential impeachment proceedings. It could also squeeze vulnerable Republicans by forcing them to go on the record. Many Republicans, so far, have attempted to stay away from the burgeoning scandal consuming the White House.

The move isn’t without risk, however, particularly for some Democrats in pro-Trump districts. And it could open Democrats up to another front of GOP criticism, as Republicans demand more power in the investigation, including the ability to issue subpoenas and call their own witnesses.

House Minority Leader Kevin McCarthy (R-Calif.) and other top House Republicans have complained repeatedly that Pelosi has violated past precedent by refusing so far to hold a full House vote authorizing the inquiry.

“Unfortunately, you have given no clear indication as to how your impeachment inquiry will proceed — including whether key historical precedents or basic standards of due process will be observed,” McCarthy said in a letter to Pelosi earlier this month. “In addition, the swiftness and recklessness with which you have proceeded has already resulted in committee chairs attempting to limit minority participation in scheduled interviews, calling into question the integrity of such an inquiry.”

White House Counsel Pat Cipollone also vowed the administration wouldn’t cooperate with Democrats’ probe, saying the process was “illegitimate” and “constitutionally invalid” in the absence of an inquiry vote.

“In the history of our nation, the House of Representatives has never attempted to launch an impeachment inquiry against the president without a majority of the House taking political accountability for that decision by voting to authorize such a dramatic constitutional step,” Cipollone wrote to Pelosi.

Some Democrats have supported calls for a vote on the floor, hoping it could bolster their case in court as well as silencing their GOP critics. But others have argued that it is not necessary, dismissing Republican complaints that they've been cut out of the process.

"I don't much care about the vote on the floor," said Rep. Jim Himes (D-Conn.), noting that he would vote for the inquiry if it came to the floor. "The point is that it's not required under the rules and there is absolutely no right being denied to the Republicans."

Andrew Desiderio contributed to this report.

