Senators plan to plow through a battery of hearings Tuesday for President-elect Joe Biden’s national security Cabinet nominees, but the last-minute rush means that most, if not all, will not be confirmed by the end of Inauguration Day.

The crammed schedule for the nominees — Avril Haines for director of national intelligence, Alejandro Mayorkas for homeland security secretary, Antony Blinken for secretary of state, Janet L. Yellen for treasury secretary and Lloyd J. Austin III for defense secretary — is a result of compound delays caused by factors including the Georgia Senate runoffs, paperwork disputes and partisan gridlock. Fallout from the Capitol riot this month further stymied the process, and President Trump’s impending impeachment trial could slow it even more.

Even if the Senate manages to squeeze in some confirmations on Biden’s first full day in office, the road ahead is unclear for Austin and Mayorkas. Austin, a retired general whose military service ended in 2016, requires a waiver before he can take over as the Pentagon’s top civilian. Mayorkas, meanwhile, faces Republican grievances that as deputy homeland security secretary during the Obama administration, he was accused of using an immigrant visa program to secure investments for political allies’ pet projects — a charge Mayorkas has denied.

A spokesman for Biden’s transition team implored the Senate GOP to hold votes for each of his nominees just as soon as their hearings conclude.

“With our national security at stake, the pandemic costing thousands of lives every day, and our economy in a historic recession, there is absolutely no justification for Republicans to jeopardize the ability of the United States government to keep the American people safe, distribute vaccines, and put Americans back to work,” the spokesman, Andrew Bates, said in a statement. “. . . It is essential that key national security and economic leaders are confirmed and in place on day one.”

Biden cannot officially ask the Senate to confirm his nominees until he is sworn in as president at noon Wednesday. Then it is up to the Senate and its relevant committees to agree to waive normal procedural requirements to expedite those nominations to final confirmation votes. Such agreements require bipartisan cooperation — and sometimes the blessing of every senator in the chamber.

How swiftly the Senate can even get to the confirmations will be influenced also by how ably leaders are able to clear extra procedural hurdles. Because the Senate is split 50-50 between Republicans and Democrats, Vice President-elect Kamala D. Harris must visit the chamber and cast her tie-breaking vote to make Sen. Charles E. Schumer (D-N.Y.) the majority leader. Senate leaders also have to work out how many lawmakers from each party will sit on committees and affirm those choices by passing an “organizing resolution.”

Senate leaders are also discussing how to “bifurcate” their schedule over the next few weeks, so the chamber can juggle confirming Biden’s Cabinet with conducting Trump’s impeachment trial.

Of the five nominees whose hearings are Tuesday, Mayorkas faces the highest hurdles. Republicans point to a 2015 inspector general’s report, which alleged that Mayorkas had weighed in on the selection process for EB-5 immigrant visas to steer capital toward projects championed by influential Democrats. The EB-5 program gives green cards to immigrants willing to invest at least $1 million in a U.S. business employing American workers, or $500,000 if that business is located in a rural area.

GOP leaders expect that some rank-and-file senators may object to Mayorkas’s nomination, denying him a swift confirmation, though ultimately he is expected to secure Senate support, as it takes only a simple majority to confirm Cabinet nominees.

Blinken, too, is expected to face delays, as Republicans on the Senate Foreign Relations Committee are prepared to object to expediting his confirmation before receiving on-the-record answers to all of their questions for him — including any written follow-ups they submit after his hearing.

Blinken has been the subject of widespread grumbling in the GOP over complaints that he has not been adequately forthcoming about the consulting business, WestExec Advisors, he co-founded after leaving the Obama administration. Many Republicans also harbor reservations about how he would perform as the top diplomat in resumed negotiations for a nuclear deal with Iran, which the Biden team has made one of its top foreign policy priorities.

If Blinken has a smooth hearing performance, leaders expect he will have an easy confirmation — but one that happens next week at the earliest.

Yellen, meanwhile, is not expected to face serious hurdles to her confirmation, which could be one of the first to clear the Senate floor.

Haines, whom Biden has selected to serve as the nation’s spy chief, is also not expected to draw objections from Republicans and could be ready for a full Senate vote as soon as Inauguration Day. Her hearing was delayed last week, but only to accommodate Sen. John Cornyn (R-Tex.), who insisted that the Senate Intelligence Committee interview her behind closed doors after she gives public testimony. That is in keeping with the panel’s tradition and would not have been possible while lawmakers and staff were working remotely.

Finally, Austin is also expected to travel a smooth path to confirmation, provided he assures senators that he respects the tradition of civilian leadership of the Defense Department. His confirmation is expected to proceed without objection later in the week, once both chambers of Congress approve the waiver needed for him to hold the office — even though he has not been retired from active military service for the seven years required by law.

The House Armed Services Committee is expected to hold a separate hearing with Austin on Thursday in anticipation of putting that waiver on the House floor.