A make-or-break week for the Senate’s bipartisan infrastructure deal is underway with Senators expected to get a deal done, as early as, Monday.

Key senators and staff spent the weekend trying to reach a final agreement. Ohio Sen. Rob Portman, who is leading negotiations for Republicans, said the two sides were “about 90% of the way there” on a deal. Virginia Sen. Mark Warner, a top Democrat in negotiations, said he was hopeful a final bill would be ready Monday afternoon.

The bipartisan package includes about $600 billion in new spending on public works projects. One of the major roadblocks has been how much money should go to public transit, which includes subways, light-rail lines and buses.

Originally, it looked like the bipartisan group would allocate more money for transit. But Pennsylvania Sen. Pat Toomey, the top Republican on the Senate committee that oversees public transit, raised questions citing previous COVID-19 relief money that had already been given to public transit.

“Nobody’s talking about cutting transit,” Toomey said Sunday. “The question is, how many tens of billions of dollars on top of the huge increase that they have already gotten is sufficient? And that’s where there is a little disagreement.”

A Democratic aide close to the infrastructure talks said there are other issues remaining. They said details on broadband funding, as well as, whether to tap into the leftover COVID-19 relief funds previously passed by Congress are still being discussed.

Democrats are seeking a compromise to pay for the package after they rejected a hike in the gas tax, and Republicans squashed a plan to boost the IRS budget to go after tax scofflaws.

The final package would need the support of 60 senators in the evenly split 50-50 Senate to advance past a filibuster. That means at least 10 Republicans would have to vote yes with every Democratic member. Senate Majority Leader Chuck Schumer held a procedural vote last week to begin debate on the bipartisan framework. All 50 Senate Republicans voted against it.