Negotiators on Thursday were working to resolve two issues standing in the way of a bipartisan infrastructure package: a disagreement over transit funding and how to handle a broadband internet component.

A fight that popped up earlier in the week over whether to use a Medicare-related revenue source, which White House officials want to save for a later reconciliation package, has been resolved, however.

Sen. Susan Collins (R-Maine), a key member of the bipartisan group, gave reporters an update on negotiations shortly before noon Thursday, as she was en route to subgroup meeting to hammer out some of the remaining issues.

Negotiators are meeting in small groups on Thursday before most of the Senate leaves town for the weekend, although a broader meeting of the entire core bipartisan group of 10 senators has not been planned.

The bipartisan negotiators say they are on track to finalize their deal by Monday, though they may not have all of the legislative text drafted by then.

“Most of the agreements have been reached. There are a few things that are still being worked on and they largely relate to transit, highway and that split. I think we’ll be there Monday. If not so then a day or two after,” Sen. Mitt Romney (R-Utah) told reporters.

Senate Republican Whip John Thune (S.D.) confirmed that transit funding and broadband regulation remain the biggest hang-ups.

“I think the two issues right now are broadband and transit,” he said.

In the meantime, the Senate is awaiting word of an agreement from the group, which one lawmaker compared to waiting for a white puff of smoke from a papal conclave.

Even lawmakers who say they’re ready to vote next week to proceed to a bipartisan infrastructure deal aren’t sure how well the talks are really going, even though they’ve been assured by negotiators that everything is on track.

“My understanding is they’re very close,” said Sen. Kevin Cramer (R-N.D.). “I believe them, but I don’t know for sure.”

But the impasse over transit remains a tough issue to resolve.

Sen. Pat Toomey (Pa.), the ranking Republican on the Senate Banking Committee, which has jurisdiction over transit, has balked at the bipartisan group’s proposal to spend $48.5 billion on public transit, on top of the traditional 80-20 allocation of highway funding between highways and transit priorities.

Toomey says a huge prospective infusion of money for public transit would set a new precedent shifting the traditional allocation of resources from an 80-20 split in favor of highways to closer to 70-30. He also points out there is nearly $40 billion in unspent COVID-19 relief funds for transit.

Toomey has called for his committee to hold a markup on the proposed transit funding, but that request isn’t getting any support from Banking Committee Chairman Sherrod Brown (D-Ohio).

“I want a deal. I just hope we get a deal,” Brown said. “I don’t think a markup is the best way. I want to see some agreement and there’s not a lot of sentiment for public transit on [the Republican] side. They don’t really believe in the word public.”

Sen. Rob Portman (R-Ohio), one of the lead negotiators in the bipartisan group, said “transit funding has not yet been resolved.”

He suggested it could be dropped altogether to avoid further slowing the deal.

“It’s important but if we can’t resolve it, then we could leave that out. I hope not,” he said. “Democrats are not being reasonable in their requests right now.”

On the broadband internet front, Thune said negotiators are debating rate regulation, who administrates federal funding for broadband expansion and who can access those funds.

“Democrats love the idea of local governments doing it,” he said.

Sen. Jeanne Shaheen (D-N.H.), one of the negotiators, said broadband debate within the group has been “around some of the questions of administering the program, how you set up the low-cost service.”

She said she expects the issue to be resolved soon.

The negotiations ran into some more turbulence on Thursday when Environment and Public Works Committee Chairman Tom Carper (D-Del.) raised concerns about funding for drinking water and sanitation infrastructure in the proposal.

He told reporters that he wanted an additional $6 billion in funding for communities allocated through grants in legislation passed by his committee earlier this year to remain as grants instead of being allocated through revolving loan funds.

“I’m going to withhold my support until they’re fully funded,” he said, noting the Senate passed the Drinking Water and Wastewater Infrastructure Act that came out of his committee on an 89-2 vote in May.

Carper said the legislation gave local communities broad authority on how to spend federal funding and expressed concern that some of that flexibility may be lost under the bipartisan deal.

He said his bill increased funding in state revolving funds for drinking water and wastewater infrastructure to $30 billion and provided another $6 billion in grants for impoverished communities.

“Add it all up, it’s about $36 billion,” he said. “We’ve been assured that our legislation would be funded, would be fully funded, and now we’re hearing it may be moved around.”

He said the bipartisan bill would mandate a certain amount of money for lead-pipe replacement, providing significantly less flexibility that the legislation passed by the Senate in May.

Updated at 2:51 p.m.

—Jordain Carney contributed.