A $1.5 billion aid package for Egypt stalled in Congress on Tuesday, with a key senator vowing to block $650 million in previously announced military aid and House members putting the State Department on notice that they'll strenuously object to future assistance if next month's presidential election isn't free and fair.

Sen. Patrick Leahy (D-Vt.), the chairman of the Senate Appropriations subcommittee on State, Foreign Operations, and Related Programs, took to the floor of the Senate to express his "growing dismay" at the death sentences handed down on hundreds of Muslim Brotherhood supporters. Meanwhile, Republicans and Democrats on the House Foreign Affairs Committee's Middle East panel made it clear that they think future aid should be frozen if the upcoming elections are a sham.

"I am extremely disturbed by the Egyptian government’s flouting of human rights and appalling abuse of the justice system, which are fundamental to any democracy," Leahy announced on the Senate floor on Tuesday. "I am not prepared to sign off on the delivery of additional aid for the Egyptian military until we have a better understanding of how the aid would be used, and we see convincing evidence that the government is committed to the rule of law."

Leahy's announcement applies to $650 million in military aid that Secretary of State John Kerry announced following a phone call last week with Egyptian Foreign Minister Nabil Fahmy. The administration also announced they were supplying Egypt with 10 Apache attack helicopters, which aren't subject to congressional approval, for anti-terrorism operations.