Congress is coming back to Washington after Thanksgiving break and it has until Dec. 16 to approve a funding bill or the government will shut down. The preference is to pass what’s called an omnibus package that covers every governmental department for all of next year.

But it’s possible Congress may have to pass a short term extension, maybe until Dec. 23, to get all the details worked out. Negotiations are still taking place as lawmakers try to agree on the White House’s request for $37 billion in Ukraine aid and Democrats’ COVID-19 funding request–all while Republicans dislike liking omnibus bills in the first place.

Any bill will need to be bipartisan to get across the finish line. The bill has to overcome a filibuster, meaning 10 Senate Republicans must approve, and House Speaker Nancy Pelosi will likely need Republican support to pass it in the House.

Even Defense Secretary Lloyd Austin is pushing lawmakers to get this done. In a letter to Congressional leaders, Austin said operating on temporary funding would harm national security and competitiveness.

“We must break this pattern of extensive inaction. We can’t outcompete China with our hands tied behind our backs three, four, five or six months of every fiscal year,” Secretary Austin wrote.