The House and Senate are expected to convene for another rare weekend session Sunday to try to work out a spending deal that will fully restore government funding before Monday.

The two parties on Saturday appeared no closer to an accord and spent much of the day using press conferences and floor speeches to blame each other for a partial government closure that kicked in Friday at midnight after Democrats and a handful of Republicans voted to block a bill to fund the government until Feb. 16.

The Senate is now debating a second funding measure that would last till Feb. 8, but Democrats are expected to vote against this funding bill as well, raising the likelihood that the workweek will begin under a partial government closure for the first time since 2013.

Majority Leader Mitch McConnell, R-Ky., announced late Saturday that Democratic objections to speedy consideration of the Feb. 8 measure means the Senate will vote on the bill Monday morning at 1 a.m.

“I want to assure the American people we will be right back at this tomorrow, and for as long as it takes,” McConnell said on the Senate floor Saturday evening. “We will keep at this until Democrats end their extraordinary filibuster of government funding and children’s healthcare, and allow a bipartisan majority of Senators to reopen the federal government for all Americans and get Congress back on track.”

The spending fight is centered on immigration reform.

Democrats want the measure to include a provision that will protect so-called "Dreamers," illegal immigrants who came to the United States as children who have been shielded from deportation by the Deferred Action for Childhood Arrivals program. DACA, put in place by former President Barack Obama, is set to expire in March.

Republicans have refused, arguing they will take up Dreamer legislation in a separate measure that is now under negotiation and would include tough border security and other immigration reform provisions.

Democrats, like Rep. Luis Gutierrez, appear more willing to surrender on providing some federal funding for a southern border wall, a chief campaign promise by President Trump.

But they are resisting any effort to modify or end chain migration, which allows immigrants living in the U.S. legally to sponsor the entry of other relatives.

Republicans also want to reform the visa lottery system, which has also been a non-starter with Democrats.

Democrats have publicly argued that their motive for resisting the spending bill is simply because a full-year spending bill is needed, not another short-term measure which is hurting military readiness.

“It’s time to actually do a budget, and fully fund our military,” Senate Minority Leader Chuck Schumer, D-N.Y., said Saturday. “We can’t forget about urgent domestic priorities in the budget, but the military has to be given the certainty it needs.”

The House remained in session Saturday and will be back Sunday, ready for a vote on a deal, if one can be found.

Sen. Lindsey Graham, R-S.C., is floating a compromise to move the spending bill through the Senate. Democratic support of the measure would come in exchange for a pledge by McConnell to take up a moderate immigration reform bill, authored by Sens. Graham and Jeff Flake, R-Ariz.

The immigration provisions would be kept separate from the spending deal, which Republicans favor, but would also ensure Democrats a vote on the the immigration bill they favor.

Late Saturday, an aide to McConnell said Republicans are not considering that option.

“The leader and speaker have made it clear that there are no negotiations on any other bills until the government is open,” the aide said.