The fall will be dominated by a tangle of fiscal deadlines that will challenge congressional leaders looking to avoid a government shutdown and brinkmanship over raising the debt limit. (AP Photo/Susan Walsh)

If nobody on Capitol Hill celebrated in July when Congress approved transportation funding for three months, it’s because lawmakers bought themselves a little time at the expense of what could be a truly awful autumn.

When Congress returns from its August recess, it faces a tangle of fiscal deadlines that could serve as a replay of some of the most contentious battles of the past five years. Those include keeping the government open amid fierce disagreement over spending caps put in place by the so-called 2011 sequester, finding a long-term way to fund highway and transit projects and lifting the debt ceiling before default.

Dispatching with all of these issues before year’s end would be a big feat under even the most generous of circumstances, but they arrive as Congress will also be deciding whether to block the Iran nuclear deal, hosting a papal visit and dealing with a truncated September calendar due to religious holidays.

For now, Republican leaders are preaching calm and assuring the agenda can be tackled without incident.

“Each side will have to give some things they don’t want to give and we’ll get to an agreement,” Senate Majority Leader Mitch McConnell (R-Ky.) said on government spending.

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The series of contentious deadlines will hit between Labor Day and Halloween, but there is a good chance most, and possibly all, of them will be pushed to the end of the year leading to a… busy December.

Republican leaders have already conceded they can’t wrap up the appropriations work before the end of the fiscal year on Sept. 30 and will need to enact a stop-gap funding bill, or continuing resolution (CR).

And despite McConnell’s parting vow that there will be no government shutdown and no debt default, there is already a small contingent of conservatives ready to fight him along the way. That dynamic is raising concerns that the mix of fiscal deadlines could result in a repeat of the 2013 shutdown standoff that ground Washington to a halt.

What follows is a list of looming deadlines and the challenges they pose.

Sept. 30: End of the fiscal year and the deadline for funding the government

Democrats say they want a deal that raises spending caps for both domestic and defense programs and in the Senate they have successfully blocked consideration of appropriations bills as they try to force Republicans to the negotiating table. 

House and Senate GOP leaders have largely ignored their demands and have instead focused on trying to make good on their vow to consider each of the 12 annual spending bills through regular order. But filibusters in the Senate and controversy in the House over amendments concerning the display of Confederate flags have left both chambers far short of that goal with the end of the fiscal year quickly approaching.

Now the question is when negotiations will begin in earnest.

The first step toward some kind of resolution will have to take place next month when a CR will be needed to keep the government open — it’s unlikely a broader deal could be reached by the start of the of fiscal year on Oct. 1.

McConnell has not publicly said if he will support a short-term bill but he is promising there  will be no shutdown.

“I can’t tell you what will finally end up in or out of a government funding bill, but I can tell you without fear of contradiction there will be no government shutdown,” McConnell said.

Even a straightforward CR may not be easy to pass.

For instance, at least 18 House Republicans have vowed to oppose any spending bill that includes funding for Planned Parenthood, following the release of undercover videos that raise questions about the practice of harvesting tissue from aborted fetuses for research. Several Senate conservatives, including Republican presidential contender Sen. Ted Cruz, (R-Texas), have refused to rule out blocking spending bills over the issue.

Then leaders have to contend with the calendar.

Congress is scheduled to be working for just 12 days before the Sept. 30 deadline. That calendar includes several shortened days at the beginning and the end of the week, several days off in observance of Rosh Hashanah and Yom Kippur and a day devoted to the Sept. 24 visit from Pope Francis.

Reaching a final spending deal will entail not only setting funding levels, but also likely address whether any increase should be offset and whether the White House will accept any of the policy riders Republicans included in their fiscal 2016 spending bills.

End of October: When the Treasury Department estimates the government will hit its debt limit

The deadline for increasing the borrowing limit is always a moving target, but Treasury Secretary Jack Lew warned Congress in July that they will have to act before the end of October.

Congress has had to address the debt limit seven times since 2010, including the 2013 battle that ultimately led to the government shutdown.

Several of the hard-line conservatives who fought against raising the debt ceiling two years ago are now running for president and have already begun stirring controversy in the Senate.

All eyes will be on Cruz, Rand Paul (R-Ky.) and Marco Rubio (R-Fla.) as the deadline nears. Cruz filibustered the last debt limit hike in 2014 but neither he nor his fellow presidential contenders have weighed in on this year’s pending deadline.

A short-term extension is not out of the picture. But lawmakers have been largely silent on a path forward for increasing the debt limit.

The last standoff in 2014 ended when Democrats in the Republican-controlled House delivered the majority of votes needed to pass a standalone measure to increase the borrowing limit.

Oct. 29: Funding for the Highway Trust Fund expires

At the end of July, Congress successfully patched the federal highway trust fund through Oct. 29.

Leaders in both chambers say this should buy them time to come up with a long-term funding deal, but it’s not clear how that would happen given their differences.

House leaders have not yet said just how long their long-term extension would be, nor have they said how they would pay for it.

The Senate already passed a three-year highway bill but the House refused to consider the legislation over funding objections. Instead, House Transportation Committee Chairman Bill Shuster (R-Pa.) said that the House will work on a long-term bill that could be considered this fall in conference with the Senate.

Lawmakers are expected to take up that work quickly in September but there is a short timeframe for negotiations. That’s why some are already quietly discussing another short-term extension.

The three-month bill that passed in July includes all of the funding provisions that were included in an earlier House bill that paid for infrastructure spending through Dec. 18. Some aides have said Congress could just pass a second bill authorizing the money to be spread out over the remaining month-and-a-half of the year, allowing negotiators more time to reach a deal.

December

So far, December looks pretty quiet for Congress. But that could change dramatically if leaders land on short-term solutions to the fall deadlines, creating the environment for a big year-end fiscal fireworks.

The only deadline on the calendar now is a year-end vote to extend dozens of expired and expiring tax breaks known as the extenders. The well-loved tax breaks have previously created a legislative headache amid debates over how much they would add to the deficit, but the Senate Finance Committee recently passed legislation to extend the provisions without much controversy.

It’s possible those tax breaks could cruise through Congress sometime before the end of the year. But the discussion will be a lot more complicated and difficult if the debate gets tied to any of the other must-pass legislation.