Republican lawmakers are asking for an extension, and filed a two-week stopgap measure to buy more time for negotiations, but the new December 22 deadline won’t be approved without a vote in Congress this week. Democrats hold leverage in this situation because Republicans won’t have enough votes to pass the stopgap measure, or any spending plan, without at least a bit of support from Democrats.

Immigration is one of the most likely issues that could lead to a shutdown this year. Senators such as Kamala Harris, Bernie Sanders and Cory Booker have announced that they will refuse to vote on any spending package that doesn’t include DACA protections. Trump repealed DACA in September, ending the program that protects young immigrants who were brought to the U.S. illegally as children from deportation.