Kentucky Senator Rand Paul single-handedly delayed a $40 billion aid package to Ukraine last Thursday for several days, initially thwarting a bill that had already passed the House of Representatives and garnered the support of the vast majority of Congress.

In late February, Russia’s invasion of Ukraine unleashed fierce criticism from the United States and its allies and a steady stream of badly-needed military aid.

Congress passed an aid package totaling $13.6 billion back in March, but the latest congressional proposal has a price tag of nearly three times that.

Sen. Paul demanded language be inserted into the bill that would place Ukraine’s foreign aid under the scrutiny of an inspector general.

He refused an offer by Senators Chuck Schumer and Mitch McConnell to hold a vote on his proposal as an amendment, instead insisting that the language be directly inserted into the bill text and that the bill be sent back to the House for another vote.

“Americans are feeling the pain [from inflation], and Congress seems intent only on adding to that pain by shoveling more money out the door as fast as they can,” said Paul, addressing his frustrated colleagues in the Senate.

Sen. Paul’s objection prevented a unanimous agreement that would have allowed the Senate to move forward with debate on the bill and eventually a vote. The House already passed the bill 368 to 57, and strong bipartisan support exists in the Senate.

Sen. Schumer criticized Paul from the Senate floor once it became clear he would not budge on his demand:

“There is now only one thing holding us back, the junior senator from Kentucky is preventing swift passage of Ukraine aid because he wants to add, at the last minute, his own changes directly into the bill … He is not even asking for an amendment. He is simply saying, ‘My way or the highway.'”

Sen. McConnell, also representing Kentucky, implored his colleague to change his mind.

“Ukraine is not asking us to fight this war. They’re only asking for the resources they need to defend themselves against this deranged invasion, and they need help right now,” he said.

After concerns that his objection to the bill could delay its passage weeks, if not longer, Sen. Paul ultimately relented, opting not to filibuster the bill on Monday when it was being debated. The Senate voted on cloture and advanced the aid package. The vote passed, 81 to 11. Senators are expected to officially pass the bill later this week.