WASHINGTON (AP) — Maryland Sen. Ben Cardin, the top Democrat on the Foreign Relations Committee, has announced he opposes the nuclear deal with Iran.

The announcement is a blow to the White House and will make it harder for the administration to block a vote on a disapproval resolution in the Senate.

In an opinion piece in the Washington Post Cardin says, "This is a close call, but after a lengthy review, I will vote to disapprove the deal."

He says the agreement will end up leaving Iran closer to a nuclear capability.

Cardin's position is critical because he is a top-ranking Jewish Democrat.

Democrats still command enough support to sustain Obama's veto of the disapproval resolution, if necessary. They are three votes short of the number needed to block it from passing.