The scramble in Congress to pass the National Defense Authorization Act is being complicated by an effort to tie it to a needed hike in the federal debt limit.

Why it matters: The House and Senate are rapidly coming up against a series of deadlines they must address before the end of the year — or risk disrupting crucial military funding and upending the economy. Congressional leaders are now hoping they can knock out both "must-pass" priorities in one, complex swoop.

• Leaders in both chambers spent the weekend negotiating several creative ways to circumvent congressional speed blocks to complete their work before their Christmas recess.

What we're hearing: Senate Majority Leader Chuck Schumer and Senate Minority Leader Mitch McConnell have discussed a series of options for expediting passage of both the NDAA and the debt-ceiling hike they hope the House will accept.

The options, according to a senior House Democratic aide:

1. House passes the NDAA agreement and then separately passes a measure setting up a one-time, fast-track process for the Senate to pass the debt ceiling via simple majority.
2. Combine the bills and pass them as one package in both chambers.
3. The House passes the bills separately but approves a rule governing floor debate for the NDAA that would combine the two measures for consideration in the Senate.

Democratic and Republican aides told Axios they're waiting to see whether the House could find enough support for such a vote before weighing in on how they may be able to push a combined package through the Senate.

• The move is risky given its complexity and House and Senate Republicans' insistence they will not support helping Democrats raise the debt limit.
• But if McConnell and House Minority Leader Kevin McCarthy approve this process, they could convince their caucuses to go along with it.

What they're saying: House Majority Leader Steny Hoyer (D-Md.) told reporters Monday afternoon Congress will deal with raising the debt limit "this week."

• He said it's still “up in the air” precisely how, and it's "a possibility” it gets tied to the NDAA, though he wouldn't elaborate.
• The House could vote on the NDAA as early as tomorrow, sources familiar with the talks tell Axios.

What to watch: Senior Senate aides said there will likely be no amendment votes on the NDAA given they've turned to voting on the compromise bill from the House and Senate Armed Services committees.

• The move robs several senators of key votes on bills they've been pushing for months, including sanctions on the Kremlin-backed Nord Stream 2 pipeline and repealing the 2002 authorization for war in Iraq.
• Some lawmakers have already said they plan to press Schumer to hold votes on their amendments before the end of the year.