Democratic Sen. Chuck Schumer, one of Capitol Hill’s most influential voices in the Iran nuclear debate, is strongly endorsing passage of a law opposed by President Barack Obama that would give Congress an avenue to reject the White House-brokered framework unveiled last week.

The comments Monday by the Democratic leader-in-waiting illustrate the enormity of the task ahead for President Barack Obama and his team: While there’s no guarantee that Congress would ultimately reject an agreement with Iran, there’s an increasingly bipartisan consensus that Congress should at least have the ability to do so.

“This is a very serious issue that deserves careful consideration, and I expect to have a classified briefing in the near future. I strongly believe Congress should have the right to disapprove any agreement and I support the Corker bill which would allow that to occur,” Schumer said in an emailed statement to POLITICO.