• Did the President request that a foreign leader and government initiate investigations to benefit the President’s personal political interests in the United States, including an investigation related to the President’s political rival and potential opponent in the 2020 U.S. presidential election?

• Did the President – directly or through agents – seek to use the power of the Office of the President and other instruments of the federal government in other ways to apply pressure on the head of state and government of Ukraine to advance the President’s personal political interests, including by leveraging an Oval Office meeting desired by the President of Ukraine or by withholding U.S. military assistance to Ukraine?

• Did the President and his Administration seek to obstruct, suppress or cover up information to conceal from the Congress and the American people evidence about the President’s actions and conduct?

The questions themselves were unveiled by the House Rules Committee last week, when Democrats established formal parameters for their impeachment inquiry. They were described at the time as "three interrelated lines of inquiry" that the impeachment probe had centered around.

But for the first time on Thursday, House Intelligence Committee Chairman Adam Schiff, the leader of the impeachment investigation, confirmed that those queries would also be the official parameters of the public hearings as well.

Schiff also delivered those parameters to Republicans on Thursday as he formally solicited their requests for witnesses they would like to call publicly. The narrowly focused questions are likely to provoke outrage among Republicans who have indicated they would like to call a range of witnesses who may speak to subjects beyond the Democrats’ interest.

Republicans' witness list is due Saturday morning and one of Trump's top defenders says at the top of the list will be the whistleblower who first sounded the alarm about the president's posture toward Ukraine.

Rep. Jim Jordan (R-Ohio) said he doesn't know the identity of the whistleblower but said Schiff should call the person to testify.

"We'll see if he gives us any of our witnesses," Jordan told reporters on Thursday, declining to identify others that GOP lawmakers intend to request.

Republicans, including Trump, have spent weeks assailing the whistleblower as politically biased, even though the person's basic account of Trump's handling of Ukraine has been corroborated — and expanded upon — by more than a dozen high-level witnesses with more direct knowledge of the episode.

Democrats have warned that Republicans' fixation on the whistleblower is both extraneous — since his account has largely been affirmed — and dangerous, since outing the person's identity could expose him to security risks. Trump has blasted the whistleblower repeatedly and called for him to be outed.

Jordan described the whistleblower as "the name that only Adam Schiff knows," though the person's attorney has argued that no lawmakers know the whistleblower's identity; instead, it’s known by only a small circle of intelligence community officials who first received his complaint.

Jordan also sidestepped questions about whether he's about to supplant Rep. Devin Nunes as the ranking member of the Intelligence Committee when impeachment hearings move into the public domain next week — a move that some Republicans have advocated given Jordan's reputation as a dogged questioner and defender of Trump.

House GOP Leader Kevin McCarthy floated the possibility of moving Jordan to the Intelligence Committee this week.

"It's up to the leader. It's up to Devin," Jordan said when asked if he wanted to join the panel. "We want to get the truth out and get out of this bunker so the American people can see what's going on."