Four senators announced Thursday they will force a vote on a proposed $1.15 billion sale of U.S.-made tanks and other military equipment to Saudi Arabia, citing the authoritarian kingdom’s poor human rights record.

The announcement came a day before the House of Representatives votes on a bill that unanimously passed the Senate that would allow 9/11 victim families to sue the U.S. ally.

President Barack Obama has threatened to veto the lawsuit legislation, but his approval is not required if lawmakers in the Senate and House pass the resolution of disapproval to block the proposed arms sale, to which his administration gave a green light last month.

The Arms Export Control Act allows senators to force an up-or-down vote on such sales. Sens. Rand Paul, R-Ky., Chris Murphy, D-Conn., Mike Lee, R-Utah, and Al Franken, D-Minn., are sponsoring the resolution, for which they must wait 10 days for a vote.

Paul dusted off the little-used power in March and forced a vote on a proposed arms sale to Pakistan, which he lost 71-24. It’s unclear who would win a vote on selling to the Saudis.

The senators said Thursday they are concerned about how Saudi Arabia would use the new weaponry, particularly as part of its military intervention in Yemen, where it supports the country's internationally recognized government against Houthi Shiite rebels and forces loyal to longtime U.S.-backed former president, Ali Abdullah Saleh, who was forced out in 2012 after a popular revolt.

“Selling $1.15 billion in tanks, guns, ammunition, and more to a country with a poor human rights record embroiled in a bitter war is a recipe for disaster and an escalation of an ongoing arms race in the region,” Paul said in a statement.

The United Nations reported that in 2015 the Saudi-led coalition killed 510 children and wounded 667 others in Yemen. The U.N. subsequently backed off labeling the Saudi-led coalition a violator of children's rights in combat after the Saudis threatened to withdraw U.N. funding.

“The Obama Administration has recently offered over a billion dollars in weaponry to Saudi Arabia, and I think it’s in America’s best interest to call a timeout on this sale,” Franken said. “In Yemen, a Saudi coalition of fighters is unjustly killing civilians while at the same time not doing enough to address terrorism. This is dangerous for the Middle East, for our other allies, and for our nation, which is why I’m helping to introduce this bipartisan resolution.”

It's unclear who will lead the effort in the Senate to retain the arms sale. It's possible that role would be taken by Sen. John McCain, R-Ariz., who chided past criticism of Saudi conduct in Yemen, arguing rebels governing much of the country are allied with Iran.

Though apparently unpopular in the Senate, House members recently have opposed restrictions on arms sales to the Saudis.

An amendment in the House to ban the sale of cluster munitions to Saudi Arabia was defeated 216-204 in June. Rep. Rodney Frelinghuysen, R-N.J., opposing the amendment, said "the Department of Defense strongly opposes this amendment" and that "they advise us that it would stigmatize cluster munitions, which are legitimate weapons with clear military utility."

But in the House, too, opposition has stirred, with 64 representatives signing a letter circulated by Rep. Ted Lieu, D-Calif., in opposition to the sale.

The Saudi embassy did not respond to a request for comment.

The Obama administration reportedly has offered sales totaling $115 billion to Saudi Arabia as part of 42 separate deals.