Senate Majority Leader Chuck Schumer said in a floor speech Monday that the Senate will take up the legislation “this week,” saying, “I expect a hardy debate and some late nights.”

One reason late nights are expected and that will make the job of Democratic leadership more challenging is that senators are walking into a legislative minefield later this week since the relief bill is being considered under budget reconciliation rules that allow a free-flowing amendment process, meaning senators can force votes on as many amendments as they like.

That means if two Democrats break ranks, they could amend the bill with the backing of 49 Republicans.

The House passed the legislation with a provision to increase the minimum wage. But that can’t be included in the Senate’s version of the bill, according to a ruling from the parliamentarian, a little known but powerful Senate official. As a result, the Senate is expected to strip that provision out in its version of the bill, necessitating a separate vote in the House to sync up the legislation.

Republicans have so far been united in opposition to the measure, which they argue Democrats have crafted without their input and have designed to serve as a liberal wish list of agenda items. Democrats, for their part, say they are willing to work with Republicans, but will not water down a package that they say will deliver much needed aid to the American people hard hit by the pandemic.

More on the bill’s timing: Democratic leaders want their caucus to hold the line against amendments that could alter the core of the bill and ultimately derail the chances of getting the sweeping measure out of both chambers by March 14 when jobless benefits are set to expire for millions of Americans.

Once the bill passes the Senate, it will have to go back to the House for a final vote before it can go to Biden’s desk.