WASHINGTON — A small bipartisan group of senators is privately sketching out the contours of a new infrastructure package – and fresh ways to pay for it – that the lawmakers hope to sell to colleagues after negotiations between Republican senators and the White House stalled in recent days.

The nascent plan is being drafted by more than a half-dozen lawmakers, including Republican Sens. Mitt Romney of Utah, Susan Collins of Maine and Rob Portman of Ohio and Sen. Joe Manchin III, D-W.Va. On Tuesday, Romney said the group, which is divided equally between Democrats and Republicans, has come to a “pretty close consensus” on key elements of a blueprint that focuses largely on traditional infrastructure, such as roads, bridges, trains and broadband Internet.

“We’re not very far from the Biden proposal on areas where we both think it’s appropriate for an infrastructure bill,” Romney told The Washington Post on Tuesday.

The still forming compromise is expected to jettison some of President Biden’s proposals that have struggled to attract Republican support, including his plan to couple infrastructure investments with new federal aid targeting elder care and low-income families. Gone, too, are likely to be the president’s proposed funds for electric vehicles, Romney said.

For these lawmakers, any attempt to unwind the 2017 GOP tax cuts is still off the table. Instead, the senators are proposing a menu of alternate ways to pay for it, including unused stimulus funds to finance infrastructure improvements. Romney said they also would seek to rethink the way vehicle owners pay taxes – tying the gas tax to inflation, for example, while requiring owners of electric vehicles for the first time to pay similar fees. And the group has proposed generating revenue by better enforcement of current tax laws, Romney said.

“Let me make very clear that Shelley Capito is the lead on our side on this issue, and my hope is that she succeeds, and she’s worked really hard,” Collins said Tuesday, referring to Sen. Shelley Moore Capito, the West Virginia Republican who has led talks with the White House. “If those negotiations come to a stalemate, I don’t think we should give up, and thus we’re continuing to look at other proposals.”

It is unclear whether the emerging plan can win over spending-wary Republicans or Democrats who want to seize on their slim but potent majorities in Congress to usher in significant changes to the U.S. economy. Biden, meanwhile, has vehemently opposed paying for infrastructure in a way that would raise taxes on Americans making under $400,000 annually, a pledge that the lawmakers’ new proposal would, from the White House’s perspective, violate if it relies on user fees.

But narrowing the definition of infrastructure at least has earned the critical support of lawmakers like Manchin, who said Tuesday he thought the White House had already agreed to tackle it in a “separate package.” Manchin also promoted the idea of using unused coronavirus relief funds, telling reporters: “You need to look at, see what hasn’t gone out the door or what has gone out the door, hasn’t been spent yet or dedicated in any way.”

The bipartisan talks are unfolding as the negotiations between six Senate Republicans and the White House appeared to have soured, as each side accuses the other of making insufficient concessions and Republican senators blame administration aides for scuttling a deal. Republicans on Tuesday again alleged that Biden previously had agreed to take what they see as “social” spending off the table – only for White House officials to reverse course days later.

Both the White House and Senate Republicans insist they are not finished negotiating, however, and Capito said her party plans to present its next counteroffer to the Biden administration on Thursday morning. Republicans are discussing a proposal that would spend about $1 trillion over eight years, according to senators and aides, which the GOP says was the approximate top line that Biden agreed to when he met with them at the White House earlier this month.

“We’re going to hit a figure very close to what the president said he would accept,” said Sen. Roger Wicker, R-Miss., one of the GOP negotiators.

The scramble to strike a deal comes at a moment of great uncertainty in the infrastructure debate. The White House has issued a Memorial Day deadline by which it hopes to see progress, but it hasn’t explained what that means, leaving lawmakers on both sides unsure whether the president is ready to try to advance another of his economic priorities entirely through Democratic votes.

Ratcheting up the pressure, Senate Majority Leader Charles Schumer, D-N.Y., on Tuesday said he plans to move forward on infrastructure in July. In the meantime, Democrats including Manchin have signaled they are not yet ready to abandon bipartisanship – and pursue infrastructure using the same legislative maneuver that helped the party pass a $1.9 trillion coronavirus aid package earlier this year.

Without virtual unanimous support from rank-and-file Democrats, any threat from leaders to sidestep Republicans may carry little weight.

“I’m always looking for that moderate, reasonable middle if you can,” Manchin said. “It might not be as big as (progressives) want, and then you have people on the right that don’t want to do that much, or do nothing at all.”

It was only two weeks ago that Biden and his Republican counterparts met in the Oval Office for the first formal round of talks – a session both sides described as positive and productive as they affirmed their interest in securing a bipartisan deal. But Democrats and Republicans since then have struggled to find common ground, warring over even the definition of what qualifies as infrastructure.

Capito last week put forward a counter-offer on behalf of her party that largely left the scope of her package unchanged. She raised the price tag – from $568 billion to roughly $800 billion – only by extending the life of the proposal from five to eight years. Much of the money in her early blueprint still reflected planned or existing federal spending, frustrating Democrats who saw it as insufficient.

The White House followed days later by similarly standing its ground, keeping intact the president’s proposed social spending and his plan to pay for infrastructure improvements through tax increases on corporations. The move drew sharp rebukes from Republican lawmakers, who said the tax hikes in particular are still political nonstarters that would prevent them from supporting any deal.

With seemingly no solution in sight, Republicans left the last round of negotiations Friday on a dour note, expressing a fear that the two sides had only grown further apart. The finger-pointing intensified Monday, as Capito and her colleagues blamed the impasse on White House aides. Republicans alleged that Biden had been open to some of the changes they sought – specifically to take entire categories of spending off the table – only to have his staff reverse course.

White House press secretary Jen Psaki declined to confirm the details put forward by Republicans about their Oval Office meeting earlier this month. But she stressed Tuesday that the latest counteroffer was approved by Biden himself, as Republicans tried to drive a wedge between the president and his aides.

“Every single detail of that was directed by the president of the United States,” Psaki said. “He was in the Senate for 36 years, I can promise you he does not take a hands-off approach to legislating, negotiating and determining what kind of counterproposals we should put forward.”