WASHINGTON (AP) – After much delay, senators unveiled a nearly $1 trillion bipartisan infrastructure package, wrapping up days of painstaking work on the inches-thick bill and launching what is certain to be a lengthy debate over President Joe Biden’s big priority.

The Infrastructure Investment and Jobs Act clocked in at some 2,700 pages, and senators could begin amending it soon. Despite the hurry-up-and-wait during a rare weekend session, emotions bubbled over once the bill was produced Sunday night. The final product was not intended to stray from the broad outline senators had negotiated for weeks with the White House.

“We haven’t done a large, bipartisan bill of this nature in a long time,” said Senate Majority Leader Chuck Schumer. He said a final vote could be held “in a matter of days.”

A key part of Mr. Biden’s agenda, the bipartisan bill is the first phase of the president’s infrastructure plan. It calls for $550 billion in new spending over five years above projected federal levels, what could be one of the more substantial expenditures on the nation’s roads, bridges, waterworks, broadband and the electric grid in years.

Senators and staff labored behind the scenes for days to write the massive bill. It was supposed to be ready Friday, but by Sunday, even more glitches were caught and changes made.

Late Sunday, most of the 10 senators involved in the bipartisan effort rose on the Senate floor to mark the moment.

“We know that this has been a long and sometimes difficult process, but we are proud this evening to announce this legislation,” said Senator Kyrsten Sinema (Democrat – Arizona), a lead negotiator. The bill showed “we can put aside our own political differences for the good of the country,” she said.

Senator Rob Portman of Ohio, a Republican negotiator, said the final product will be “great for the American people.”

Among the major new investments, the bipartisan package is expected to provide $110 billion for roads and bridges, $39 billion for public transit and $66 billion for rail. There is also set to be $55 billion for water and wastewater infrastructure as well as billions for airports, ports, broadband internet and electric vehicle charging stations.

The spending is broadly popular among lawmakers, bringing long-delayed capital for big-ticket items that cities and states can rarely afford on their own.

Paying for the package has been a challenge after senators rejected ideas to raise revenue from a new gas tax or other streams. Instead, it is being financed from funding sources that might not pass muster with deficit hawks, including repurposing some $205 billion in untapped COVID-19 relief aid, as well as unemployment assistance that was turned back by some states and relying on projected future economic growth.

Bipartisan support from Republican and Democratic senators pushed the process along, and Mr. Schumer wanted the voting to be wrapped up before senators left for the August recess.

Last week, 17 GOP senators joined all Democrats in voting to start work on the bipartisan bill. That support largely held, with Senate Minority Leader Mitch McConnell voting yes in another procedural vote to nudge the process along in the 50-50 Senate, where 60 votes are needed to overcome a filibuster and advance legislation.

Whether the number of Republican senators willing to pass the bill grows or shrinks in the days ahead will determine if the president’s signature issue can make it across the finish line.

The bipartisan bill still faces a rough road in the House, where progressive lawmakers want a more robust package but may have to settle for this one to keep Mr. Biden’s infrastructure plans on track.

The outcome with the bipartisan effort will set the stage for the next debate over Mr. Biden’s much more ambitious $3.5 trillion package, a strictly partisan pursuit of far-reaching programs and services including child care, tax breaks and health care that touch almost every corner of American life. Republicans strongly oppose that bill, which would require a simple majority for passage. Final votes on that measure are not expected until fall.