When President Joe Biden sits down with the top congressional leaders on Tuesday, he will see some familiar faces: Mitch McConnell, Chuck Schumer, and Kevin McCarthy, with whom he’s engaged in a high-stakes standoff.

The fourth principal, Hakeem Jeffries, is a different story.

The House minority leader is not a longtime collaborator with the president. In fact, he has a largely undefined relationship with Biden. He has been something of a side player in the debt ceiling drama that is quickly approaching a fiscal doomsday cliff. And the White House — sticking to a no-negotiation on the debt ceiling posture — has had little need to lean on him.

But with talks set to pick up steam, the New York Democrat could soon be playing a more pivotal role. Should a compromise bill be reached between the White House and congressional GOP leadership, it would almost assuredly require some — if not many — House Democratic votes to get through that chamber.

Two years ago, the solution for Biden would have been easy: Let then-Speaker Nancy Pelosi — the premier vote wrangler of her generation — do the work. Now it’s on Jeffries, someone the White House is still getting to know. The two only had their first known substantive meeting this past January, when Biden huddled with the top Democratic leaders at the start of the new Congress.

In short, the first pivotal test of his and Biden’s ability to work together could take place with the global economy on the line. And how that goes will provide an early glimpse of what Democrats hope will be the dominant partnership in Washington in 2024 if Biden wins a second term and Democrats win back the House. Not everyone in the party is sure of what to expect.

“All of this is going to need a level of coordination we haven’t yet seen,” said a senior Democratic House aide. “This will be the first time things are tested.”

The two only had their first known substantive meeting this past January, when Biden huddled with the top Democratic leaders at the start of the new Congress.