Sens. Jeff Merkley (D-OR) and Ed Markey (D-MA) introduced a joint resolution of disapproval on Thursday that aims to block the U.S.-Saudi nuclear deal, allowing the Democrats to force a vote on the deal when the chamber returns from recess.

It appears unlikely at this point that the GOP-controlled Congress will vote to block the deal, with most Republicans expressing support for it, but some GOP holdouts have voiced their concerns. The agreement would tee up the possibility of nuclear enrichment inside Saudi Arabia and lacks the safeguards applied to deals with the United Arab Emirates and some other U.S. allies.

The resolution could come up for a vote on Nov. 29 at the earliest. House Democrats have introduced a similar resolution to block the deal.

Both Merkley and Markey said that the deal is effectively a covert path to a nuclear weapon for Saudi Arabia.

Merkley said it is “unacceptable” to make such a deal without “ironclad protections” to ensure that the program cannot be used to create a nuclear weapon. He said that nations pursuing ostensibly peaceful nuclear energy programs must agree to forego enrichment and reprocessing and allow rigorous inspections.

“We can’t sleepwalk into a decision this consequential,” Merkley said. “The law gives Congress the power to review and block a deal like this, and the Senate will now have the chance to fulfill its statutory responsibility before it’s too late.”

Markey was even more direct.

“The US-Saudi nuclear deal is about megatons, not megawatts. Trump should not be sharing nuclear bomb technology with a nation that US intelligence says may want nuclear weapons,” Markey said. “Even worse, the deal fails to meet the nonproliferation Gold Standard, by allowing Saudi Arabia to enrich uranium, an essential step to producing a bomb, but not requiring the strongest international inspections. This deal is the starting gun for a Middle East nuclear arms race. Congress must reject it.”

Saudi Crown Prince Mohammed bin Salman has said openly that Saudi Arabia would pursue nuclear weapons if Iran were to obtain a nuclear bomb.

In a press release, Merkley and Markey also noted that President Donald Trump has said publicly that he would tie the deal to Saudi normalization with Israel but that no such conditions exist within the language of the agreement.