The Senate worked on an infrastructure package in a Saturday session.

WASHINGTON — The Senate convened for a rare weekend session on Saturday, with Majority Leader Chuck Schumer encouraging the authors of a bipartisan infrastructure plan to finish writing their nearly $1 trillion bill so that senators can begin offering amendments.

Several senators had predicted that the text of the bill would be ready for review late Friday or early Saturday, but it was not done when the Senate opened for business late in the morning. Nor was it ready when Schumer came to the floor in the early evening.

“I’ve been informed the group is working hard to bring this negotiation to a conclusion, but they need a little more time,” Schumer said. “I’m prepared to give it to them.”

Schumer, D-N.Y., said earlier in the day he understood that completing the writing of such a large bill is a difficult project, but he warned that he was prepared to keep lawmakers in Washington for as long as it took to complete votes on both the bipartisan infrastructure plan and a budget blueprint that would allow the Senate to begin work this year on a $3.5 trillion social, health and environmental bill.

“The longer it takes to finish, the longer we will be here, but we’re going to get the job done,” he said.

The bipartisan plan calls for $550 billion in new spending over five years above projected federal levels. A draft bill circulating Capitol Hill indicated it could have more than 2,500 pages when introduced. It’s being financed from funding sources that might not pass muster with deficit hawks, including repurposing untapped COVID-19 relief aid and relying on projected future economic growth.

Among the major investments are $110 billion for roads and bridges, $39 billion for public transit and $66 billion for rail.

There’s also $55 billion for water and wastewater infrastructure as well as billions for airports, ports, broadband internet and electric vehicle charging stations.