A group of bipartisan House lawmakers unveiled their own framework for an infrastructure package, as Democrats wrestle with how to advance President Biden’s ambitions for a sweeping economic agenda and whether to restructure the plan to win Republican votes.

Mr. Biden’s decision to end talks with Senator Shelley Moore Capito of West Virginia, the lead Republican negotiating a package on behalf of the Republican conference, has left prospects for a bipartisan deal unclear, even as the administration has encouraged lawmakers to continue working toward that goal.

The so-called Problems Solvers Caucus, a group of 29 Democrats and 29 Republicans in the House, put forward a plan for $761.8 billion in new spending, as part of an overall $1.249 trillion plan over eight years. While the plan outlines funding pots for highways, roads, waterways, broadband, airports and veterans’ housing, it does not address how to pay for the legislation — one of the biggest hurdles that has long prevented agreements on infrastructure in the past.

The leaders of that caucus, Representatives Josh Gottheimer, Democrat of New Jersey, and Brian Fitzpatrick, Republican of Pennsylvania, have been in touch with a group of senators who have been quietly discussing their own framework. Those senators, led in part by Rob Portman, Republican of Ohio, and Kyrsten Sinema, Democrat of Arizona, huddled for hours Tuesday evening, but did not emerge with any details of specific funding levels or a timeline for releasing a framework.

But the administration also faces pressure from liberal Democrats, who are eager to abandon the search for the 10 Republican votes needed to overcome the filibuster and instead opt to muscle a fiscal package through using the fast-track budget reconciliation process.

“Every day that is wasted trying to get Republicans on board is another day that people can’t go back to work because they don’t have child care; another day without investing in millions of good, union jobs, another day that we lose further ground on the climate crisis,” said Representative Pramila Jayapal of Washington, the chairwoman of the House Progressive Caucus. “Further delays jeopardize momentum and allow Republicans to block progress for the American people with no end in sight.”

Using that process, however, will be fraught as all 50 Senate Democrats and nearly all House Democrats will need to be united around the plan for it to clear both chambers.