The unveiling of the articles will be the culmination of a nearly three-month impeachment inquiry centering on Trump’s alleged efforts to pressure Ukraine to investigate his political rivals — and the president’s subsequent efforts to block Democrats’ access to key witnesses and documents.

The decision to move forward with specific impeachment charges is the most significant move yet for the year-old Democratic House majority, a legacy-defining moment for Speaker Nancy Pelosi that sets up a Senate trial for Trump in early 2020.

Earlier Monday evening, senior Democrats, including House Judiciary Committee Chairman Jerry Nadler (D-N.Y.), huddled in Pelosi's office to discuss the articles of impeachment. Some Democrats were still advocating for an obstruction of justice charge against Trump Monday, but it was unclear if there was enough support for such a charge within the Democratic Caucus.

Nadler and other top Democrats were mum as they exited Pelosi's office Monday night.

“There will be some announcements tomorrow morning,” House Foreign Affairs Committee Chairman Eliot Engel (D-N.Y.) said as he left the meeting.

Nadler and House Intelligence Committee Chairman Adam Schiff (D-Calif.) are expected to lead the press conference, which is scheduled to begin at 8:45 a.m., according to multiple Democrats. The other committee chairs investigating Trump will also attend, but Engel told reporters that Pelosi is not expected to participate.

Emerging from a Judiciary Committee meeting late Monday, Rep. David Cicilline (D-R.I.) said the panel’s Democrats plan to re-convene at 8 a.m. Tuesday morning ahead of the press conference. He said the articles of impeachment were still being finalized.

“We’re going to work throughout the night.” Rep. David Cicilline.

“Our staff has been working on this for quite a period of time,” Cicilline said. “We’re going to work throughout the night.”

Judiciary Committee aides huddled late into the evening and were prepared to hunker down for an all-nighter as they discussed the plan to unveil articles the next morning. A steady stream of lawmakers exiting the meeting indicated no final decisions had been made about which articles of impeachment would ultimately be included in the morning announcement.

The closed-door strategizing followed a day-long hearing at which House impeachment investigators presented their case against Trump, alleging that the president violated his oath of office and should be impeached for trying to pressure Ukraine to help his reelection campaign.

The nearly 10-hour hearing was more of a formality as Democrats finalize their charges against the president, and lawmakers on the panel spent much of the day sparring with eachother over partisan talking points.

The president’s counsel refused to participate, leaving Republicans on the House Judiciary Committee to serve as Trump’s defense and attempt to undermine Democrats’ impeachment arguments.

House Democrats allege Trump abused his power by soliciting assistance from Ukraine to smear his political rival, former Vice President Joe Biden, in exchange for military aid and a coveted Oval Office meeting. Trump then attempted to block Democrats’ investigation into the scandal by ordering top aides not to testify and refusing to comply with subpoenas.

Those allegations will form the basis of at least two charges against Trump -- abuse of power and obstruction of Congress.