The new session of Congress that is set to begin Thursday promises to be much like the old session of Congress that ended Tuesday.

The House and the Senate will formally convene for the 113th Congress just hours after they wrapped up a notably unproductive and acrimonious two years with a desperate series of votes aimed at averting economic calamity and minimizing political chaos.

The result is that the next Congress will start with the bitter aftertaste of the last, which left a long list of unfinished business and political scores to be settled.

“Everyone’s just as tired as I am, I’m sure,” Senate Majority Leader Harry M. Reid (D-Nev.) said late Tuesday as he put the finishing touches on the 112th Congress.

At the very last minute, lawmakers agreed to a toughly negotiated package that avoided severe austerity measures but set up more battles in the coming weeks, including over mandated across-the-board spending cuts, the debt ceiling and a new bill to fund the government after the current agreement expires in March.

Find out all about the new faces in the 113th congress — sort by state, party, gender and chamber and see who was elected where and why.

“In the first three months of the new year and the new Congress, we have set for ourselves three potential crises in the making,” said Rep. Gerald E. Connolly (D-Va.), who said he cast a “hold-your-nose vote” for the bipartisan deal to avert the “fiscal cliff.”

For Republicans demoralized by the passage of the fiscal rescue plan, Thursday brings another bitter pill: Rather than sweeping Democrats from power in November, the GOP lost ground in both chambers of Congress.

In the House, Democrats picked up eight seats. On Thursday, Republicans will hold 233 seats to Democrats’ 200. Two seats will be vacant.

More significantly, the Senate will remain in Democrats’ solid control; the party has an expanded majority of 55 seats, up from 53.

Though most of the new Congress will look the same as the old, the next session will boast a record number of women — 20 in the Senate and 81 in the House — and will be more racially diverse, with more black, Latino and Asian lawmakers. For the first time, a Hindu, Tulsi Gabbard (D-Hawaii), will take office in the House. And Hawaii’s Mazie Hirono (D) will become the first Buddhist senator.

The first openly gay senator, Tammy Baldwin (D-Wis.), will be seated, as well as the first openly bisexual member of either chamber, incoming congresswoman Kyrsten Sinema (D-Ariz.).

In the House, ceremonies marking the new session start Thursday morning with a prayer service, followed by an opening session at noon and swearing-in ceremonies in the afternoon.

Once deliberations begin, Speaker John A. Boehner (R-Ohio) has assured angry colleagues, the chamber will start work on legislation to provide federal aid to states ravaged by Hurricane Sandy.

To the outrage of lawmakers from Sandy-affected areas, Boehner and Majority Leader Eric Cantor (R-Va.) dropped plans late Tuesday to hold a vote on a supplemental spending plan before the old session ended, a decision that will force the Senate to restart debate on a $60 billion aid package it passed last week. A Democratic leadership aide said the plan is to try to quickly pass whatever the House sends over.

In the Senate, the new session is expected to begin with some drama: Sen. Mark Kirk (R-Ill.), who suffered a stroke almost a year ago, plans to climb the stairs of the Capitol to make his return.

In the coming days, Senate leaders are set to consider two competing proposals to address some of the chamber’s procedural rules for filibusters, which allow the minority to stymie the initiatives of the majority.

A bipartisan group of senior senators has made recommendations that would lessen the ability of a lone senator or a small group to impede progress through delaying tactics — or the mere threat of those tactics — that sometimes prevent Senate leaders from even considering certain bills.

Sen. Carl Levin (D-Mich.), a chief architect of the plan, noted that “it takes a week just to overcome that threat or that filibuster just to get to debate the bill. We spend days and days and days trying to get a bill to the floor so it can be debated.”

The plan, also backed by Sens. John McCain (R-Ariz.) and Charles E. Schumer (D-N.Y.), would allow a filibuster on final passage of legislation, meaning that a bill could fail with fewer than 60 votes.

Younger Democratic senators, mostly elected in the past six years, say that a lawmaker carrying out a filibuster should be required to actually speak at length on the chamber floor. If that senator eventually gave in, the majority would be able to proceed to final passage on a simple 51-vote majority.

Sen. Jeff Merkley (D-Ore.), a lead proponent of this idea, called “the silent secret filibuster” a “deadly” procedural tactic. “If you’re voting for more debate and you’re going to take up the time of this institution,” he said in a floor speech Wednesday, “. . . then you should have the courage of your convictions to make your case on this floor before your colleagues.”

Reid has resisted attempts to overhaul the filibuster rules, but the majority leader has also grown frustrated with GOP filibusters on even the most basic procedural steps and has signaled an openness to the changes.

Senate Democratic aides said Reid and his GOP counterpart, Sen. Mitch McConnell (Ky.), are trying to negotiate rule changes to make the Senate more efficient. If those negotiations fall through, however, Democrats are prepared to force some changes unilaterally, the aides said.

On Wednesday, Reid’s deputy, Sen. Richard J. Durbin (Ill.), told Merkley and Sen. Tom Udall (D-N.M.) on the Senate floor that “I’m not sure we’re going to achieve exactly what you want,” but that their efforts are “going to end up in a change in Senate procedure.”