WASHINGTON — Congress returned to Washington on Monday after a monthlong recess facing a spate of pressing deadlines and partisan flashpoints, including key decisions on funding the government, addressing gun violence and investigating President Donald Trump.

Lawmakers haven't left themselves much time to deal with any of these issues: The House, for instance, is scheduled to be in session for only 45 days through the end of the year.

Here’s some of what to expect from a crowded fall session:

Guns

Immediately after the shootings in El Paso, Texas, and Dayton, Ohio, last month, Republicans appeared ready to take action and craft a bipartisan compromise with Democrats to try to reduce gun violence. Trump himself suggested several times that he would favor stronger background checks, but later wavered. After the latest shooting in Odessa, Texas, there has been little talk of potential movement in the negotiations on Capitol Hill.

Democrats are still slated to make the issue a priority. House Speaker Nancy Pelosi, D-Calif., told her caucus during recent conference calls that it is “the most urgent issue” on the docket, and that Senate Majority Mitch McConnell, R-Ky., will have “hell to pay” if he doesn’t act.

“The pressure is on. We need McConnell to give us a clean vote,” she told her members. “We have to keep our foot on the gas on this issue. We must get McConnell to act. Cannot let it go away.”

The House Judiciary Committee is expected to hold a key markup this week — one delayed by a week because of Hurricane Dorian — on several Democratic-sponsored bills to prevent gun violence. One would ban high-capacity magazines, another would prevent people who are considered a risk to themselves or others from accessing guns, and still another would prevent individuals who are convicted of misdemeanor hate crimes from owning firearms. The Judiciary Committee will also hold a hearing on Sept. 25 to discuss how to deal with military-style assault weapons.

Democrats passed two major gun measures this year, including one that would establish new background check requirements for firearms transfers between individuals without gun licenses. McConnell has not taken up the bill. In a letter to Senate Democrats, Senate Minority Leader Chuck Schumer, D-N.Y., said last week that he is urging Republicans this September to debate and vote on the bill.

McConnell has not yet committed to a vote on any gun legislation, only saying in an interview with conservative radio host Hugh Hewitt last week that the Trump administration is in the process of “studying what they are prepared to support, if anything.”

“I expect to get an answer to that next week,” he said. “If the president is in favor of a number of things that he has discussed openly and publicly, and I know that if we pass it it’ll become law, I’ll put it on the floor.”

Impeachment

Democrats added a few hot-button items to their Trump investigative agenda over the break, including fresh probes into whether the president is financially profiting from his office — and hearings at which his alleged former paramours are expected to testify.

Pelosi’s careful stance on impeaching the president has not changed. “The public isn’t there on impeachment,” she reiterated to House Democrats during a conference call in late August — though she didn’t close the door on the possibility of moving forward in the future.

“It’s your voice and constituency, but give me the leverage I need to make sure that we’re ready and it is as strong as it can be,” she told rank-and-file members. “If and when we act, people will know he gave us no choice. If he cannot respect the Constitution, we’ll have to deal with that.”

Nadler has acknowledged that his committee is already conducting an impeachment inquiry, which will determine whether they decide to recommend the filing of articles of impeachment against the president. More than half of the House Democratic caucus, 134 members, has already voiced support for an inquiry.

The House Judiciary Committee is on track to escalate its impeachment investigation this week, taking it first formal vote, to set up procedures governing hearings moving forward.

The vote, expected Thursday and confirmed to NBC News by a source familiar with the committee's plans, will include language that is expected to follow the procedures the panel used in 1974 during the Nixon impeachment proceedings.

Last week, Nadler issued a subpoena to Acting Homeland Security Secretary Kevin McAleenan for documents related to Trump’s alleged attempts to offer pardons to people carrying out the administration’s immigration policies. He said that the move was part of his panel’s impeachment probe.

“As the Committee continues its investigation into whether to recommend articles of impeachment, it is imperative that we are able to obtain information about ongoing presidential misconduct and abuses of power,” Nadler said in a statement about the subpoena.

And as part of the committee’s wide-ranging investigation into whether to recommend articles of impeachment, the Judiciary panel plans to hold hearings as soon as October on the Trump campaign’s alleged hush money payments to Playboy model Karen McDougal and adult-film star Stormy Daniels during the 2016 campaign, a committee aide familiar with the matter told NBC News.

Democrats are also investigating what they say are the president’s violations of the Constitution’s emoluments clause by accepting and encouraging foreign governments to pay to stay at Trump resort properties without congressional approval.

The House Oversight and Judiciary Committees sent a series of letters last week requesting documents and information regarding Vice President Mike Pence’s trip last week to the Trump International Golf Links and Hotel in Doonbeg, Ireland, 180 miles away from his official meetings in Dublin. They also requested information about the president pushing the Trump National Doral Miami as the next venue to host the G7 Summit.

Government funding

The House is expected to consider a short-term spending bill next week that would keep the government funded past Sept. 30, House Majority Leader Steny Hoyer, D-Md., said in a letter to House Democrats last week.

Hoyer said that the House has done its work by sending appropriations bills to the Senate that would cover 96 percent of government funding, but the Senate has failed to introduce similar spending bills.

“As we wait for them to complete their work so that we can begin conference negotiations, a continuing resolution will be necessary to prevent another government shutdown like the one we experienced earlier this year, which harmed thousands of American families,” Hoyer wrote in the letter.

In previous years, Congress has extended government funding into December, placing the odds of a shutdown closer to the holidays.

Trump last signed a spending bill into law in mid-February, which funded the government through September. That followed a lengthy government shutdown fight this year over the president’s request that Congress fund a wall along the U.S.-Mexico border. But Democrats rejected his demands, prompting the president eventually to declare a national emergency on the border. The administration is now in the process of raiding money from the military in order to finance the wall’s construction.

Trade

Trump and many key congressional Republicans have been calling for the approval of the United States-Mexico-Canada Agreement, known as the USMCA, that was negotiated between the three countries last year.

On a third conference call with House Democrats during the August recess, Pelosi reiterated that she had key concerns with the deal because of labor standards, prescription drug prices, environmental protections and concrete enforcement mechanisms.

House Ways and Means Chairman Richard Neal, D-Mass., said during the call that there is “good momentum” for a deal with the administration and Republicans on the renegotiated trade deal. He said that Trade Representative Robert Lighthizer has been receptive to proposals to address some of the Democratic caucus concerns and that the ball is now in the administration’s court.

With everything else on Congress's plate, it could be difficult for Democrats and the administration to ultimately come to an agreement, especially with the 2020 presidential race heating up.