Sen. Richard Blumenthal (D., Conn.) on Tuesday blocked an up-or-down vote on legislation meant to hold VA employees accountable for misconduct.

The Democratic lawmaker denied a motion for unanimous consent after Sen. Marco Rubio (R., Fla.), a GOP presidential candidate, brought the VA Accountability Act of 2015 to the Senate floor for immediate consideration.

The bipartisan bill would allow Department of Veterans’ Affairs Secretary Robert McDonald to remove or demote a VA employee because of poor performance or misconduct. The House passed the legislation at the end of July. However, Rep. Jeff Miller (R., Fla.), who introduced the bill in the House, said before its passage that McDonald does not support the legislation.

President Obama has threatened to veto the legislation, calling it "counterproductive" and insisting that it would "have a significant impact on VA’s ability to retain and recruit qualified professionals and may result in a loss of qualified and capable staff to other government agencies or the private sector."

Meanwhile, an independent assessment released last month found that the Department of Veterans’ Affairs network of health facilities faces "crises in leadership and culture" and other problems warranting a "system-wide reworking" of the Veterans Health Administration.

Various VA inspector general reports published in recent months pointed to serious flaws at specific VA facilities as well as waste at the Veterans Benefits Administration.

Concerned Veterans for America CEO Pete Hegseth slammed Blumenthal in a statement Tuesday for standing with "Washington special interests and corrupt VA bureaucrats" by blocking the vote.

"Almost every day, there is a new story of VA employees engaging in misconduct or corruption–demonstrating that a year and a half after the wait list scandal began and after promises of change from the Obama Administration and Congress, a toxic culture still infects the VA," Hegseth stated.

If the Senate does not move the legislation through regular order as quickly as possible, Hegseth said, lawmakers will be sending "a message to the millions of veterans who use the VA that they are not a priority for the United States Senate."