The "agreement in principle" clinched by House Republicans and the White House late Saturday to raise the nation's borrowing limit was the culmination of mad-dash negotiations over the course of the past week that regularly stretched late into the night.

But the marathon is far from over, and there is still little certainty the nation will avoid a default as both parties now work to consolidate support around the emerging package.

The agreement -- which would raise the debt ceiling for two years, freeze spending on domestic programs, increase spending on defense and veterans issues, impose some new work requirements on federal food assistance programs and change some rules around energy permitting -- was meant to include provisions that could sway members of both parties to vote for it.

Yet even ahead of the deal's announcement, House members on both the left and right were already balking at some of the details said to be included in the package. Republicans who had demanded larger spending cuts threatened to withhold their support, while Democrats voiced concern that new rules on social safety net programs would send more Americans into poverty.

"No one claiming to be a conservative could justify a YES vote," wrote Rep. Bob Good, Republican of Virginia, on Twitter.

For House Speaker Kevin McCarthy, the upcoming battle to secure the votes of at least half of his party's members -- as he has promised -- will be a defining moment for his hard-won young speakership.

President Joe Biden, too, will be under pressure to deliver votes from Democrats, dozens of which will likely be necessary for the bill to secure passage. Biden spoke Saturday with the top Democrat in the House, Rep. Hakeem Jeffries, who will be responsible for marshaling his members.

"The agreement represents a compromise, which means not everyone gets what they want. That's the responsibility of governing," Biden wrote in a statement late Saturday, saying the agreement "protects my and congressional Democrats' key priorities and legislative accomplishments."

He said he "strongly" urged the House and Senate to pass it.

Speaking late Saturday, McCarthy said text of the package would be finalized by Sunday, setting up a required 72-hour period for members of Congress to review the bill. He said he hopes the House will vote as soon as Wednesday, allowing precious little time for each party's leaders to secure sufficient support.

In the Senate, any one member can slow down the process by as long as a week, adding another layer of uncertainty as Washington rushes to avoid default.

Last week, Treasury Secretary Janet Yellen set June 5 as the date the government will run out of cash to pay its bills in full and on time. The US has never before defaulted, and economists predict the consequences would be catastrophic.

Republicans in the conservative House Freedom Caucus have already warned they are prepared for a furious battle if they consider the compromise a major retreat from the Republican position. Ahead of the deal's announcement, they raised alarms over the length of the proposed debt ceiling hike and the push to roll back spending to 2023 levels, when many wanted to cap spending at 2022 levels.

"It is going to be a substantial price to earn my vote and that price is the meaningful, substantial, transformative fiscal reform necessary," said Texas Republican Rep. Chip Roy, a conservative and member of the House Rules Committee, on Thursday.

One conservative House Republican, Rep. Dan Bishop, predicted smaller cuts to spending would amount to "war."

The agreement in principle reached by the White House and House Republicans will lift the debt limit for two years and roughly cap non-defense spending to current fiscal year levels for 2024 and 2025, according to a source familiar with the negotiations.

As part of the deal, the White House has also appeared to have made concessions to House Republican negotiators on work requirements for people receiving food stamps.

The agreement reached on Saturday phases in food stamp time limits on people up to age 54 that will then sunset in 2030, while also exempting veterans and people who are homeless from these limits. The current work requirement for the program, formally called the Supplemental Nutrition Assistance Program or SNAP, only applies to certain adults between the ages 18-49.

The agreement does not make any changes to Medicaid and prevented certain changes to the Temporary Assistance for Needy Families (TANF) program called for by Republicans.

Still, many Democrats have warned that additional work requirements on social safety net programs are a nonstarter, and the White House lambasted the GOP position on the idea as "cruel and senseless" last week.