Sen. Rand Paul blocked a vote to permanently reauthorize the 9/11 Victims Compensation Fund, which provides financial assistance for first responders suffering from 9/11-related medical issues. Paul prevented the Senate from voting to approve the bill through unanimous consent because of its cost.

"It has long been my feeling that we need to address our massive debt in the country," Paul, a Republican from Kentucky, said on the Senate floor. "And therefore any new spending ... should be offset by cutting spending that's less valuable. We need to at the very least have this debate."

Sen. Kirsten Gillibrand of New York, who introduced the measure for unanimous consent Wednesday, said that she was "deeply disappointed" by Paul's actions. Under Senate rules, any one senator can propose that a bill be considered for unanimous consent, but one senator can also block it. The bill can still be brought to the floor for debate and a full vote.

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"Senator Paul may have turned his back on our first responders today, but now we have a filibuster-proof bipartisan support of 73 cosponsors in addition to myself," Gillibrand told reporters Wednesday.

Senate Majority Leader Mitch McConnell brought the House bill to the Senate calendar this week, hoping to vote on the measure before the August recess. McConnell spoke with first responders at the end of June, who urged him to hold a vote.

Gillibrand and Senate Minority Leader Chuck Schumer, also from New York, urged McConnell to bring it to a floor vote this week.

"We have carried the football 95 yards down the field, we are on the five-yard line, but there's often fumbles on the five-yard line and you don't get it over the line for the touchdown. The person who has got to carry the ball with us now is Mitch McConnell. He's got to put this bill on the floor," Schumer said.

The bill passed in the House earlier this month in a final vote of 402 to 12. The fund was permanently reauthorized through 2092 after a blistering Capitol Hill testimony by first responders and comedian Jon Stewart, in which he lambasted members of Congress for their lack of compassion in providing necessary funding for the health care needs of 9/11 responders.

During Stewart's testimony last month, he at times broke down in tears, shouting at the lawmakers and calling them "shameful."

"I can't help but think what an incredible metaphor this room is ... a filled room of 9/11 first responders and in front of me, a nearly empty Congress. Sick and dying, they brought themselves down here to speak to no one ... shameful," said Stewart.

At a press conference ahead of the vote, Stewart told reporters, "It's very difficult to watch a House and Senate with a trillion-dollar deficit try and balance that budget of $10.2 billion over 10 years on the backs of 9/11 victims and first responders."

"Don't be nuts here – this is necessary it is urgent, and it is morally right," he added.

The bill was named after first responders who passed away from health complications related to the 2001 attacks, including Luis Alvarez, who died of cancer earlier this month. Alvarez, a former NYPD detective and 9/11 responder, testified before the House panel alongside Stewart shortly before his death.

"This fund isn't a ticket to paradise. It's to provide our families with care," said Alvarez. "You all said you would never forget. Well, I'm here to make sure that you don't," Alvarez said to a room of loud applause.