(Photo: AP)

WASHINGTON, Oct. 28 (Xinhua) -- US House is expected to vote on Thursday on the impeachment inquiry procedures as House Democrats move closer to a public phase of the investigation, Democratic House Speaker Nancy Pelosi announced Monday.

In a letter to colleagues, Pelosi wrote that Thursday's vote is not necessary but ultimately aims to "eliminate any doubt as to whether the Trump administration may withhold documents, prevent witness testimony, disregard duly authorized subpoenas, or continue obstructing the House of Representatives."

A Democratic aide told TheHill news daily that it would be subject to a full vote by the House on Thursday.

This would be the first formal vote on the new impeachment process by the House since Pelosi threw her support to an inquiry in September.