The Senate voted Monday to end debate and move on to a final confirmation vote on President Trump's nominee for deputy secretary of defense.

A confirmation vote on Pat Shanahan, a vice president at Boeing, will likely be held Tuesday following a partisan scuffle in the Senate over the slow pace of confirmations. Shanahan could fill a key spot in the Pentagon for the Trump administration as it attempts to shore up depleted forces and prepare for a buildup next year.

Shanahan was approved by the Armed Services Committee on June 28 and Senate Majority Leader Mitch McConnell blamed Democrats for a delay on the floor. Sen. John McCain gave a fiery speech last week urging the chamber to put partisan politics aside for defense nominees.

For their part, Democrats under Sen. Chuck Schumer were reluctant to move quickly on Trump's picks during a larger fight over healthcare. Democratic Sens. Kirsten Gillibrand, Bernie Sanders, Cory Booker, Edward Markey, Kamala Harris and Elizabeth Warren still voted against moving forward on the nomination.

Sen. Orrin Hatch, R-Utah, said Shanahan is highly qualified for deputy defense secretary and has a reputation as a strong business leader that would compliment Defense Secretary Jim Mattis.

"If Secretary Mattis wants Shanahan, I believe the Senate should speed his nomination so the good work can continue," Hatch said.

Shanahan had a difficult confirmation hearing before Armed Services and McCain publicly berated him for vague answers and threatened to hold up the nomination. The senator relented after Shanahan filed amended answers to his written committee testimony.

Confirmations have been slow under the Trump administration, partly due to delays on Capitol Hill, delays in naming candidates and the withdrawal of some picks.

Richard V. Spencer, Trump's nominee for Navy secretary, was passed to the full Senate by Armed Services last week but it has not voted yet. The committee held a hearing on four other nominees last week and will consider five this week.

The position of Army secretary, the civilian who oversees the largest military service, remains unfilled and the administration has announced no new nominee after two of Trump's previous picks dropped out.