Joe Biden on Thursday unveiled a “historic economic framework” that he said would make the US more competitive and resilient, touting the $1.75tn plan to expand the nation’s social safety net and confront the climate crisis as a victory for consensus and compromise even as the path forward remained uncertain.

The president, who delayed his departure to Europe to finalize the proposal, cast the emerging deal as a once-in-a-generation opportunity to restore American leadership and show the world that democracies can still deliver in the 21st century.

His remarks at the White House followed a visit to Capitol Hill on Thursday morning, where he pleaded with House Democrats to unite behind the agreement, saying that his presidency – and their political futures – depended on the passage of his domestic agenda.

“I don’t think it’s hyperbole to say that the House and Senate majorities and my presidency will be determined by what happens in the next week,” he said, according to a source familiar with his private remarks to the caucus.

The visit set in motion a flurry of activity on Capitol Hill, as Democratic leaders, eager to deliver Biden a legislative victory, ramped up pressure on progressives to accept the “framework” as a done deal, paving the way for them to join moderates in passing a related $1tn bipartisan infrastructure bill. With Republicans mostly aligned against the plan, Pelosi only has a handful of votes to spare.

“When the president gets off that plane, we want him to have a vote of confidence from this Congress,” she told her fractious caucus on Thursday morning. “In order for us to have success, we must succeed today.”

Twice during the course of the hour-long meeting, Democratic lawmakers rose to their feed and began to chant: “Vote, vote, vote.” But their enthusiasm was quickly tempered as her caucus’s most liberal members dug in.

Leaving the meeting on Thursday, the Washington congresswoman Pramila Jayapal, chair of the House Progressive Caucus, said the deal was a sign of “tremendous momentum” but that her position remained unchanged: the bills must move in tandem.

“I feel a bit bamboozled because this was not what I thought was coming today,” said congresswoman Cori Bush, a progressive from Missouri. Speaking personally about working a low-wage job and struggling to afford housing and childcare, Bush said she wasn’t ready to give up on fighting for policies that would lift her constituents from similar circumstances.

Putting it more bluntly, congresswoman Rashida Tlaib, a Democrat from Michigan, said she was a “hell no” on the infrastructure bill if there was not a simultaneous vote on the larger spending plan.

During a press conference, Pelosi did not commit to holding the vote on Thursday, saying only that the party was “on a path to get this all done”. Working franticly to advance the legislation, the framework was swiftly translated into a 1,684-page bill released shortly before a House rules committee hearing on the measure.

“This is not the end of the process,” said congressman Jim McGovern, a Democrat from Massachusetts and the chair of the committee, affirming multiple times during the hearing that the social policy package would not be ready for a vote on Thursday. “This bill will continue to be perfected.”

Complicating negotiations for Democratic leaders was a lack of certainty from the key holdouts, Senators Joe Manchin of West Virginia and Kyrsten Sinema of Arizona. Both sounded hopeful that a deal was within reach, but stopped short of offering their firm support.

“After months of productive, good-faith negotiations with Biden and the White House, we have made significant progress on the proposed budget reconciliation package,” Sinema said, adding: “I look forward to getting this done.”

Manchin also did not commit to supporting the legislation he played a significant role in shaping. Asked whether he would vote for the plan, he said only that its fate was presently “in the hands of the House”.

After months of prolonged negotiations, the proposed framework is far smaller in size and scope than the $3.5tn package Biden initially envisioned. Even so, the president claimed a pre-emptive legislative achievement on par with those enacted by Franklin D Roosevelt and Lyndon Johnson.

“Any single element of this framework would be viewed as a fundamental change in America. Taken together they’re truly consequential,” Biden said during remarks from the East Room at the White House, pointing to new spending on childcare and climate mitigation.

“If we make these investments, we will own the future,” he added.

The package would make substantial new investments in childcare and caregiving as well as transitioning the US economy away from fossil fuels. According to the White House, the framework would put the US on track to meet the president’s pledge to slash planet-warming emissions by 2030.

Among the other provisions in the bill are free preschool for every three- and four-year-old, expanded health coverage under the Affordable Care Act, and what the White House is calling the largest “effort to combat climate change in American history”.

Stripped from the package were plans to provide 12 weeks of federal paid family leave and two years of free community college; ambitious climate initiatives and efforts to lower prescription drug prices. A proposal to expand Medicare to cover vision, dental and hearing was pared back to just hearing.

Democrats spent the last several weeks haggling over plans to pay for their agenda, amid opposition from both Manchin and Sinema to various revenue-raising proposals. On Wednesday, a novel plan to tax billionaires’ assets was tossed aside after Manchin said the plan carried “the connotation that we’re targeting different people”.

To offset their spending, Democrats said they would raise an estimated $2tn by increasing taxes on corporations and the highest earning Americans, and by rolling back some of the Trump administration’s tax cuts passed in 2017. It honors Biden’s campaign pledge that he would not raise taxes on Americans earning less than $400,000 a year, according to the White House.

After weeks of frenetic negotiations, Democrats were scrambling to cobble together a deal that the president could tout when he travels to Rome, the Vatican, and then to the United Nations climate conference, known as Cop26, in Glasgow, Scotland, where he hopes to point to the accord as evidence of the US’s commitment to confronting the climate crisis.

“We are at an inflection point,” Biden told House lawmakers. “The rest of the world wonders whether we can function.”

Internal disputes over the bill delayed its passage for weeks, as Democrats blew past self-imposed deadlines in an effort to find a compromise that could satisfy the broad ideological expanse of their party.

The result is a bill that reflected the limits of their governing coalition, Biden said, indicating that this was the best deal Democrats could hope to achieve with paper-thin majorities and unified Republican opposition.

“No one got everything they wanted, including me,” he said. “But that’s what compromise is. That’s consensus. And that’s what I ran on.”

The Vermont senator Bernie Sanders, chair of the powerful budget committee, called the framework a “major step forward” but warned that there were also “major gaps” in the legislation. He cited the lack of paid family and medical leave for workers and the failure to expand Medicare benefits to include dental and vision as well as herding, a major priority for the senator.

Without all 50 senators, the legislation will not pass.