WASHINGTON (AP) — Tea party conservative Sen. Ted Cruz on Tuesday vowed to speak in opposition to President Barack Obama’s health care law until he’s “no longer able to stand,” even though fellow Republicans urged him to back down from his filibuster for fear of a possible government shutdown in a week.

“This grand experiment is simply not working,” the Texas freshman told a largely empty chamber of the president’s signature domestic issue. “It is time to make D.C. listen.”