Republicans have left themselves 10 days to complete an ambitious end-of-year agenda that includes tax reform, government spending and several other must-do bills.

Lawmakers will begin tax reform negotiations in earnest now that Republican leaders have named members to serve on a conference committee that will work out differences between House and Senate tax legislation.

Republicans are optimistic they will come up with a compromise bill in time to vote on a measure by Christmas, said Majority Leader Kevin McCarthy, R-Calif. McCarthy added an extra week to the House schedule, telling lawmakers there will be a session the week of Dec. 18, presumably to consider a compromise tax bill.

“We all know we have important work to do, including passing the historic Tax Cuts and Jobs Act, for the American people,” McCarthy said before the House adjourned Thursday. “I think that will be an excellent Christmas present.”

But Congress must address other critical unfinished business, and if the House plans to adjourn by Dec. 22, that leaves at most ten days to complete a packed legislative agenda, if lawmakers are in session every weekday.

Lawmakers have yet to come up with a bipartisan agreement to fund the federal government for the rest of fiscal 2018, and instead chose to pass a short-term measure that expires on Dec. 22.

Democrats and Republicans are at odds over spending amounts for domestic and military budgets and Democrats are demanding a provision that would legalize so-called Dreamers.

Republicans and Democrats are also at odds over how to reauthorize the federal Children’s Health Insurance Program, which expired on Sept. 30. The short-term funding bill lawmakers passed last week includes emergency funding for states, but only until the end of the month.

Congress must take up a bill to reauthorize a critical provision of the Foreign Intelligence Surveillance Act, or FISA, which is used to help prevent terrorism on U.S. soil.

The federal flood insurance program is also set to expire after Congress gave it a two-week extension that expires with government funding on Dec. 22. The House passed a five-year reauthorization measure in November, but the Senate has yet to come up with a proposal.

Senate Banking Committee Chairman Mike Crapo, R-Idaho and ranking member Sherrod Brown, D-Ohio, are working on a bipartisan deal, panel spokeswoman Amanda Critchfield told the Washington Examiner.

The parties are at odds over how to reform the program, which is in debt. Senators representing flood-prone areas are fighting to protect residents from higher costs while other lawmakers are looking for ways to protect taxpayers through privatization, better flood mapping and an end to insuring properties that have flooded repeatedly.

Democrats questioned GOP leaders last week about the long list of unfinished business lawmakers hope to complete by Christmas.

“Let’s say we have nine legislative days,” House Minority Whip Steny Hoyer, D-Md., asked McCarthy Thursday. “Can the leader give us some idea how we might accomplish the work that needs to be done in that time frame?”

As of Friday, the House schedule for next week included action on two banking bills, the Financial Institution Customer Protection Act and the Investor Clarity and Bank Parity Act.

The House will also vote on a bill improve the effectiveness of financial sanctions against Iran and a second bill to require oversight of the sale of commercial aircraft to Iran.

Senators will start the week with a vote to advance Steven Grasz to be U.S. Circuit Judge for the 8th Circuit. Senators will also vote on the nominations of Don R. Willett to be Circuit Judge for the 5th Circuit and James C. Ho to be US District Judge for 9th Circuit.